I like the idea that when SB life starts to parallel FTL life, it jogs a sense of familiarity or deja vu in people. This is totally consistent with what happened to Kathryn. Poor girl. I shudder to think of where her heartless body might turn up.
I do wonder how much power Regina still has over people in SB. Once she set the curse in motion, could she still control people? The curse implanted the false memories/histories into people’s minds, but does Regina have the ability to implant particular memories as need arises now that Emma is mucking about with things?