Session 0 idea

Long time lurker on this sub, wanted to hear what Reddit thought:

So it's been a long while since my group played dnd, mostly due to scheduling issues, and they all pretty much suspect we will never play again.

But they're wrong.

I'm planning to surprise them with an invite to a session that would serve as a session 0. Since I don't want them to know about it, they can't prepare characters and backstories ahead of time. So to do this, I've had 2 ideas:

1. Invite then IRL to a character creation session after which we do an encounter or something.

2. Create exactly enough pregenerated characters, invite them so they dont suspect anything, and launch them into a session with these characters randomly handed out.

I want to do the 2nd option, and I was thinking to end it off letting most (or all) of them die against the BBEG, or something, and then sending them home to create characters that want to finish what this 'original' group tried to do, and so to basically play through the motivation for their characters to become adventurers.

Do you, fellow dungeoneers, think this might work? Any concerns of tips will be much appreciated!