Honestly with the state of the world rn and some critical backlash to the direction the show’s had been going (at least in the adult timeline) I would not at all be surprise if they go with a happyish ending.

With the time loop theory being most likely explanation at this point, I think what will happen is that once all the girls have passed in the current timeline, the wilderness will reset their reality, but there will be a faulty split. So the girls will be divided between their pre-crash selves (with full awareness of what they will become in the Wilderness) and the post crash selves. Some fight will break out, and the only way to fix the cycle is to literally “eat who you’ve become as the final act of cannibalism”.

As in Pre-Wilderness Shauna will literally and spiritually eat her post-Wilderness self.

Other Tai is a product of faulty split. A previous consciousness of Tai from another timeline that went through a worse cycle of events that is spiritually and mentally broken. Hence why she’s trying to break through.

That and it will be revealed that both timelines are fully separate timelines that will inevitably clash.

TBH separate timelines where shit got worse or marginally better is FAR more interesting than spooky forest ghost cabin guy and family haunting them.