I’m in the camp that believes if they all wake up – they’re screwed like Jefferson. So, they will be whole but also very disoriented and continuously piecing the two worlds together in order to survive and deal with all the dualities. I think, instead of wiping out the alternate Selves, the Storybrooke and FTL Selves will merge to make the characters and situations more interesting but some folks just may not be able to make the leap and they’ll join Belle down in the basement. Hmm, Fairy Tales meets One Flew Over The Cuckoo’s Nest and Marat/Sade. Could be nice and twisted, actually.
It could be, the prophecy gets fulfilled and the curse gets broken, everyone remembers (briefly or permanently) then as a fail safe a new layer of the curse descends onto the the cursed, also entrapping any would be saviors and restarts itself a little bit smarter each season – sort of like a computer chess game that learns its human counterpart’s board strategy and incorporates it into each new game until it locks out every option of the human ever winning. Henry likes games, ask him about it. 😉