I don’t see why there would be a new thread unless the new devs decide otherwise. There's nothing stopping the new team from keeping the same thread for future updates since it’s still the same game, in principle. I get your optimistic point of view, but I think Flynn made it pretty clear how serious the reasons were behind his leaving. Even if he had the time, I doubt he’d be in the right headspace to work on the game. He kind of passed the game on to whoever would take over, so I think his wishes were pretty final on that front.
It’s not that I wouldn’t want Flynn to come back to his game, even in a different role in its production, but I really doubt that’s something he would want or that it’s even possible for him. I can imagine that for him, deciding to leave everything behind must have been a really tough moment. Let’s just wish him some peace and hope things get better for him in his life.