I haven't specified what I meant when I said the AIs could return to the Home program with their memories restored "after". After the full campaign, after the individual acts? Originally my thought was "the campaign", but now that we know the length we're dealing with, i'm not too sure. The whole idea had a nice twist of Copium, of course-- I'm not ready to give up this idyllic postgame counter-canon, maybe if I brute force it we can have both things be true! But with things being what they are... oh baby, this does NOT make my AU the nice easy alternative.
First, and perhaps least interesting: my original concept. The AIs are stuck in the new timeline until the campaign ends. In this situation, Gordon's mental health is FUCKED. No wonder the "water" is affecting him so badly, his brain must be an active tornado of blame and panic. Frankly, I don't think he'd agree to this if it was going to take that long. Maybe he didn't realize just how much the game would take to the adaptive coding? He was expecting just a jaunt with his friends, not to have them scattered to the winds with new lives while he got to meet literal new lives.
And the second option. The "merciful" one. The one where they get to leave between acts. How do you come home from that?
One minute you're a mixologist more or less living in early retirement, enjoying video games, flying kites, finding ways to occupy your days. And then, for a few hours, none of that has ever been true. You've spent the last twenty years apart from most of these people. You stopped coloring your hair to try and touch up the grays a long time ago, those chemicals and pigments in the dyes could be used to save lives instead of catering to vanity. It's been just as long since you could put on our rocket boots without needing to stop and switch out your leg prosthetic. And just as quickly, you're woken up into a world where the truth about your reality sinks in as freshly as it did six-- six, only six, what do you mean only six-- years ago. Your appearance isn't a body to you anymore. It's a character model. No matter which one you choose, it will never be correct.
At least you're not the one who has to get into bed at night pressed against a husband who remembers moving on after decades without you.