The errata introduced changes to specify spell slots' classes. I was wondering if those changes could somehow prevent coffeelock cheese in the spirit of this Jeremy Crawford tweet to interpret class features as reserved for that specific class?
Quote from the tweet:
DMs, if you allow multiclassing in your game and someone is tempted to abuse the combination of Flexible Casting and Pact Magic, remember this: one way to read the multiclass rules is that your Pact Magic slots are useless for any non-warlock thing besides casting spells.
Coffeelock is a sorc/warlock multiclass that exploits these mechanics:
You can use your sorcery points to gain additional Spell Slots, or sacrifice Spell Slots to gain additional sorcery points. You learn other ways to use your sorcery points as you reach higher levels.
Pact Magic Spell Slots
You regain all expended spell slots when you finish a short or Long Rest.
The "coffeelock" character uses flexible casting to convert warlock spell slots into sorcery points then turn those sorcery points into spell slots, short-resting to recover warlock spells slots then turn those into more sorcery points, virtually giving that character unlimited spell slots so long as the character does not take a long rest.
The Errata (As of April 2020)
Changes were made to Spell Slots in D&D 5E's Players Handbook to specify that spell slots now belong to a class. Changes emphasized below in bold italics:
Spell Slots (Sorcerer)
The Sorcerer table shows how many spell slots you have to cast your sorcerer spells of 1st Level and higher. To cast one of these sorcerer spells, you must expend a slot of the spell's level or higher. You regain all expended spell slots when you finish a long rest.
Spell Slots (Warlock)
The Warlock table shows how many spell slots you have to cast your warlock spells of 1st through 5th level. The table also shows what the level of those slots is; all of your spell slots are the same level. To cast one of your warlock spells of 1st Level or higher, you must expend a spell slot. You regain all expended spell slots when you finish a short or long rest.
Ignoring sleep mechanics and Jeremy Crawford's tweet, I wish to know if these errata changes could be interpreted in a clear way that prevents the "coffeelock" exploit?
In what way do these changes actually impact the game?
A positive answer to my main question, if it exists, will help in Adventurers League and Rules-As-Written sessions without having coffeelock arguments sprawl over to sleep mechanics and sage-advice territory. This will keep rulings concise and efficient.