What Lies in the Shadow of the Snowman by Lolost

Long-time lurker, first posted theory. I’m following a train of thought that I started in a comment section earlier today. I don’t think I’ve heard anyone mention this idea.

After LA X, I was in the camp that what we’re seeing in the ALT is really what happens after some event later in season 6. Jack does something that leads to his neck being cut and that causes the “reset” of the flight not crashing. But – what if our Losties are experiencing what Desmond went through?

I was thinking about “The Substitute,” and the other parallels to the meaning of this title. Back in the hatch days, Kelvin was waiting for his substitute to help him take care of saving the world – “What did one snowman say to the other?” Desmond joins Kelvin. They’re “trapped,” waiting for their “substitute” (candidate who knows “what lies in the shadow…”). Kelvin dies, Desmond is solo, Locke enters – and Desmond thinks he may be his substitute. Locke doesn’t know the code response, but he takes over the world-saving, until he too feels trapped by this.

Substitutes were no longer needed to push the button in the hatch when Desmond imploded the whole thing via the fail-safe key - which then shot him into his own "ALT"... It's all happened before.

Desmond had déjà vu in his own ALT - microwave oven; seeing Charlie on the streets; etc. But – overall things were great in ALT at first, he was with Penny.

Of course then he bumped his head and ended up back on the island, trying to save Charlie from dying.

So – what if when (either Jughead goes off, or some other Incident occurs if two different things) – the Losties are shot into their own ALTs, just like Desmond was. Some have a déjà vu thing going on; some see connections to others from the Island world like Desmond did.

The question is: Will the Losties over the course of season 6 “bump their heads” in various ways in their ALTs and end up back in 2007 Island reality? Are they all going through what Desmond did after pushing the fail-safe key? Have we really seen this all before, but it was previously isolated to just Desmond?

This is the only idea I can think of that would make me change my mind that LA X doesn't show the last scene of the show when the flight doesn't crash; the ALTs are "real" to each character - but they'll somehow end up leaving their separate ALTs and will end up back on the island snowglobe. Then the "real" resolution of the show will take place, once the realities are joined again.

Anything not plausible here? Feedback welcome. Thanks.