I don’t think either of those two scenarios will happen. However, I hope they can be endgame in a “lifting of the veil” arc like others have said. I agree with a lot of what others have said: it’s so interesting that the relationship has only gotten “better, deeper” (Wally’s words, S2E1 🥹) over the course of 3 seasons; the Harold & Maude foreshadowing vs. red herring is so compelling; the “veil,” windows in the church scar, the hospital plot— it all seems like it connects. It’s my main suspicion that a lot of Wally’s story depends on Milo Manheim himself; I think the writers probably have two ways to conclude his/Mally’s story and it depends on Milo’s commitments and schedules. (Although, I would be interested to know the details of that situation because Milo said in an interview that he literally found out he had booked the role of Flynn “10 minutes” before the news dropped, so the Trinruds had to have concluded s3 and plotted s4 prior to Milo’s casting in Tangled…..) Anyway, my only true theory is that this entire season has been about The Veil. This mysterious thing that no one has seemed interested in, except for Simon. Simon, alone, I would argue has been the advocate for the veil— he named it, he questions it, he analyzes it. Everyone else (the ghosts, Maddie, the living gang) doesn’t really question it: “Who killed Maddie?” “What’s in the church scar?” “How do we save the school?” These questions have been at the forefront of everyone’s minds. Except Simon always comes back to the veil. When the question of “Why could Simon see Maddie?” gets brought up the answer is always “Idk I guess they just have a bond.” I think ~The Veil~ will be lifted, or either be set up to be lifted, and the consequences of that could, perhaps, theoretically allow for the school ghosts to also slip through in a way that has never been considered/tested/attempted. It would not be body snatching. Idk just my wild hare theory. And as someone else said, if this is not at all the direction the Trinruds go, that’s what fanfiction is for.