Although it hurts all the martial adepts, and the swordsage's recovery method totally should be house-ruled because it sucks,...
No, the Feat Adaptive Style Doesn't Recover Expended Maneuvers
It requires a long explanation that's hard to grasp if used to doing it differently, but the feat Adaptive Style has the side effect of rendering some maneuvers unexpended after it's used, and after it's used twice the feat Adaptive Style can get back a martial adept's original maneuvers in their unexpended state.
The feat Adaptive Style permits a martial adept to change his readied maneuvers as a full-round action instead of spending 5 minutes to do so. A readied maneuver that was a readied maneuver when the change began and is still a readied maneuver when the change ends has not changed, and those readied maneuvers that are unchanged retain the same expended or unexpended states as when the change began.
However, new readied maneuvers resulting from the feat Adaptive Style's use are unexpended.
Earlier today, my coworker said that I made an error in a memo and to change it. I erased the error and wrote it again. Later, my boss said, "You need to change your attitude," and I said to him, "Done, and it's the same attitude." Then, while driving home from my former job, my car got four flat tires, so I removed the tires and put them back on. After my car scraped up the driveway, I walked into my house, and my wife told me to change my greasy shirt. And as she slammed the front door behind her, I tried to figure out why she was so angry that I'd changed my shirt to the same shirt.
This is not change as most folks understand it.
Ready versus Change
Here are the general rules from the Maneuvers Readied section on page 5. In part, it reads...
At the beginning of each day, a martial adept chooses some of the maneuvers she knows as her "readied" maneuvers (the number is determined by her class and level). These are the maneuvers she can initiate. A martial adept can change her readied maneuvers at any time, but doing this requires 5 minutes of rest, meditation, prayer, or the performance of various practice routines. The specific details depend on the martial adept’s class.
Then each martial adept class includes a description of how each martial adept class must ready maneuvers and how each martial adept class can change maneuvers.
- The crusader's Maneuvers Readied reads, in part, "You ready maneuvers by praying
for 5 minutes. The maneuvers you choose remain readied until you decide to pray again and change them. You need not sleep or rest for any long period of time in order to ready your maneuvers; any time you spend 5 minutes in prayer, you can change your readied maneuvers" (9).
- The swordsage's Maneuvers Readied reads, in part, "You ready your maneuvers by meditating and exercising for 5 minutes. The maneuvers you choose remain readied until you decide to meditate again and change them. You need not sleep or rest for any long period of time to ready your maneuvers; any time you spend 5 minutes in meditation, you can change your readied maneuvers" (16-7).
- The warblade's Maneuvers Readied reads, in part, "You ready your maneuvers by exercising for 5 minutes. The maneuvers you choose remain readied until you decide to exercise again and change them. You need not sleep or rest for any long period of time to ready your maneuvers; any time you spend 5 minutes in practice, you can change your readied maneuvers" (21-2).
Emphasis, in all cases, mine. There's a difference, then, between getting to ready maneuvers and getting to change maneuvers.
Here’s the feat from page 28 of Tome of Battle.
With just a short period of meditation, you can change your maneuvers and tactics to meet the threat you currently face.
Prerequisite: Crusader, swordsage, or warblade level 1st.
Benefit: You can change your readied maneuvers at any time by taking a full-round action. If you’re a crusader, your current granted maneuvers are lost and you gain new granted maneuvers as if you had just readied your maneuvers for the day.
Normal: You can change maneuvers only by spending 5 minutes to do so.
When a martial adept is allowed, at the beginning of the day after his 5 minutes of doing what he must, to ready his maneuvers, he picks from among all his Maneuvers Known and makes any of them his Maneuvers Readied.
When a martial adept is allowed, after his 5 minutes of doing what he must, to change his readied maneuvers, he picks Maneuvers Readied that he wants to change from, picks Maneuvers Known he hasn't readied that he wants to change to, and replaces one with the other. Expended maneuvers and unexpended maneuvers that remain Maneuvers Readied keep their states, and new Maneuvers Readied are unexpended. Using the feat Adaptive Style makes this 5-minute process take only a full-round action.
That's why the feat Adaptive Style doesn't make readied expended maneuvers unexpended. The feat only changes readied maneuvers. (Yes, it gains crusaders new granted maneuvers, but that's not an issue.)
Vaunred the Walker (ToB 121-2) has the maneuvers fire snake and shadow stride among his Maneuvers Readied. He initiates the fire snake maneuver, expending it. Later he takes a full-round action to use the feat Adaptive Style. He picks the maneuvers fire snake and shadow stride to change. He opts to change them to the maneuvers death from above and mountain hammer--which are among his Maneuvers Known but not among his Maneuvers Readied--, and, when the full-round action concludes, those become Maneuvers Readied and can be initiated while the maneuvers fire snake and shadow stride remain Maneuvers Known but aren't readied.
Vaunred can't change the maneuver fire snake to the maneuver fire snake because that's not a change. He can't change the maneuver shadow stride to shadow stride, either, because that's not a change. He can't change shadow stride to fire snake because then he'd have fire snake as a Maneuver Readied twice, and a Maneuver Readied is already a Maneuver Readied. He can't even change both fire snake and shadow stride simultaneously with each other because then he'd still have the same Maneuvers Readied as he had before, and that's not a change to his Maneuvers Readied. Vaunred could've taken a full-round action to use his special action (his recovery method explained in the swordsage class description (16) and under the heading Recovering Expended Maneuvers (40)) to recover the expended fire snake maneuver, instead of using the feat Adaptive Style to change it, if he wanted to use the fire snake maneuver next round.
"Can You Make That Clearer?"
Read the sidebar Keeping Track of Readied and Expended Maneuvers (38). Then get 1 set of Tome of Battle maneuver cards. From those cards assemble a martial adept's Maneuvers Known pile. No multiples of a maneuver in your Maneuvers Known pile; a maneuver's either a Maneuver Known or it's not. From those Maneuvers Known assemble the martial adept's Maneuvers Readied pile that he gets after 5 minutes at the beginning of the day. (Bear in mind that the Maneuvers Readied pile comes from the Maneuvers Known pile; thus only 1 Tome of Battle deck is needed per martial adept class the character possesses; this exercise assumes a single-classed martial adept.) Then imagine the martial adept spends 5 minutes to change some of the Maneuvers Readied or, if preferred, takes a full-round action to use the feat Adaptive Style to do it. Then change some of the Maneuvers Readied.
This is the hard part. If, when finished changing maneuvers, a card in the Maneuvers Readied pile is the same card as when the change started, the card has not changed, even if an attempt was made to change it. The change didn't take place, and nothing about its expended or unexpended state has altered either. Just like it's not a different card unless it's changed to a different card, it's also not a different maneuver unless it's changed to a different maneuver.
To change readied maneuvers, the potentially new Maneuvers Readied must be different from the current Maneuvers Readied. Otherwise, there's no change.
When allowed to change Maneuvers Readied, the martial adept doesn't put all his cards--both his Maneuvers Readied and his Maneuvers Known--into his Maneuvers Known pile and pick new Maneuvers Readied from among all of those cards; that's what the martial adept does at the beginning of the day when he gets to ready his Maneuvers Readied.
Instead, when allowed to change his Maneuvers Readied, the martial adept picks cards from his Maneuvers Known pile (which is already minus his Maneuvers Readied pile), puts those cards into his Maneuvers Readied pile, and then puts cards from his Maneuvers Readied pile into his Maneuvers Known pile until he's at his required number of Maneuvers Readied. New cards in the Maneuvers Readied pile are unexpended, but expended old cards in the Maneuvers Readied pile remain expended because they're not changed. They're still the same cards.
Once the martial adept has taken the 5 minutes to pick his Maneuvers Ready for the day, until tomorrow he can only change his Maneuvers Ready.
"But the FAQ Says Otherwise."
The FAQ says
If a character uses the Adaptive Style feat (ToB 28) after he has expended some of his readied maneuvers, does he choose new readied maneuvers equal to the maximum number he can ready, or equal to the number he hasn’t yet expended?
Using the Adaptive Style feat completely resets the character’s readied maneuvers, making them all available for use. If you’re a crusader, you also reset your granted maneuvers.
Don't ignore the question! The question asks, "Does a martial adept who uses the feat Adaptive Style get to change all his readied maneuvers or just the unexpended ones?" The FAQ only answers that the martial adept who uses the feat Adaptive Style does get to change all of his readied maneuvers even if they're expended, that the new maneuvers are available for use, and that crusaders get new granted maneuvers.
The question doesn't ask about leaving maneuvers unchanged after using the feat Adaptive Style. The question asks only about changing all readied maneuvers or just unexpended ones. So the FAQ answers that question.
(I think many folks read that part of the FAQ and jump to the answer rather than reading the question. I also think that many who read it read the character's readied maneuvers and think that means all characters' readied maneuvers. It doesn't; it means the readied maneuvers of the character in the question. That is, the questioner's character who wants to change all his readied maneuvers using the feat Adaptive Style. It's a FAQ; the question can't be ignored.)
The part of the answer saying that the new readied maneuvers are all available for use is a thing. The martial adepts' Maneuvers Readied sections say that martial adepts "begin an encounter with all [their] readied maneuvers unexpended, regardless of how many times [they] might have already used them since [they] chose them" (9, 16, 22). Emphasis mine. But the text was unclear on maneuvers' expended or unexpended states if maneuvers went from the Maneuvers Known pile to the Maneuvers Readied pile during an encounter. With the FAQ's clarification that they're available for use, that's not an issue anymore. Martial adepts needn't track the expended or unexpended state of maneuvers in their Maneuvers Known pile and need only concern themselves with the expended or unexpended state of Maneuvers Readied. That's... good and improves playability.
"That Sucks for the Swordsage!"
It does. The normal swordsage recovery method, wherein a swordsage recovers 1 expended maneuver "by using a full-round action to quickly meditate" (16), even if doing so doesn't provoke attacks of opportunity, is horrible. But house ruling the swordsage's recovery method is a better solution than letting this feat do something it doesn't do.
However, keep in mind that the feat Adaptive Style does let a swordsage change his Maneuvers Readied with his not-readied Maneuvers Known as a full-round action, so at least all those new Maneuvers Readied can be initiated. Further, if the swordsage uses the feat Adaptive Style a second time, he can change his Maneuvers Readied to anything in his not-readied Maneuvers Known pile, including those he put there the last time he used the feat.
That means it takes the swordsage using the feat Adaptive Style 2 full-round actions instead of 1 to get back the maneuvers he started with, and that does suck. But that's not the fault of the feat Adaptive Style, but an issue with Tome of Battle's authors not realizing the crippling nature of the swordsage's recovery method. Were it reprinted today, the swordsage would doubtlessly have a much less egregious method of recovering expended maneuvers, and folks wouldn't feel the need to kludge the feat Adaptive Style into doing something it doesn't.