Think of it this way:
This particular kind of game is a bunch of prompts and levers to help you to (1)work together, (2)in the moment, to build compelling fiction.
This style of play still has room for prep work (e.g. coming up with interesting locations and characters outside of play, and mapping out how they fit together — your "fronts" or "threats") but you're not prepping what happens, because everyone is going to be working together to decide what happens (c.f. "play to find out what happens").
On top of that, this specific thing — the fate of the player characters: boom, dead in the ground, all together, finito, the end — is a very extreme outcome. Their physical state and survival is a major locus of narrative tension in all those combat scenes and adventures. Keeping that tension going without anyone suddenly, clumsily snapping the thread and de-facto ending the game isn't just the goal of the game mechanics, it's also the goal of the conversation — the other players won't let you.
Just forcing through won't work. (You may "win," but it's going to be ugly and tedious getting there.)
So, instead: have a different conversation.
Alright. Imagine you're all writers on Star Trek or something, and you want to make that episode where the Enterprise blows up and then everything gets reset over and over again by Time Particles until they figure out how to stop it from blowing up. And you walk into the writers' room and you say: "I've got it! The Enterprise blows up. Everyone's dead."
Okay. Aaand? You need to give them more or they can't actually help you write it. Even to just write that "Enterprise blows up" scene before you get to all the Time Particle stuff, they need more information or it's going to come out wrong — you're in "Surprise! The end… or is it? Haha!" first-act mode and they're in last-act "Well, this is the end, bring out the big guns and really earn it" mode. Doesn't work.
Holding your cards close to your chest for the sake of the cool surprise works when you're presenting the story for an audience, it doesn't work when you're co-creators who need to build the story together. (And, even then, your audience understands narrative cues, too, so when you kill the entire crew of the Enterprise five minutes into the episode, they absolutely know you that's just the hook and you're not suddenly going to roll credits and fill up the rest of the hour with a Kung Fu rerun.)
No, what you do is you sell your big twist as part of your pitch. "I've got it! The Enterprise blows up. Everyone's dead. And then it happens again and again and again." Now you're on the same page and you can work out the details together.
There are a lot of approaches you can take.
You could just tell them straight-up. This is what you want to happen, here's why, let's work together to build it. You might actually have an absolute blast with this because the players can suspend the usual stakes and work together to describe cool stuff about their dramatic-but-temporary demise.
You could hide your big twist a little bit and still get buy-in. Just say "Hey, can I take over the storytelling for a few minutes, I've got a big twist idea that'll be worth your while, I promise?" — Just be prepared for them to say "No." (Or "Why??")
You could even loop them into it more directly. One example is "Gamechangers" in (another PBTA game) Apocalypse World: Burned Over, which has everyone agree to a narrative or procedural twist (anything from opening up a new part of the setting to "we rotate GMs now" or "we change game systems") that's unlocked by players spending advances.
I honestly think the finer differences between specific choices aren't that important here. Just recognize this:
- You are defying the normal flow and goals of the fiction-building conversation at the table — that's a problem for the group (you pushing one way while the other players, unknowingly, push the other way) rather than just you vs. game mechanics.
- The problem will almost-magically disappear as soon as you and the other players get on the same page about this deviation from how the game normally works.