I think the marriage on vacation lots thing on the recent patch was because people do get married at Disney parks so I'm sure they wanted that to be available in Batuu. But I would not be upset if I was wrong and the next pack was centered around improved romance and wedding options. Couples dancing please, if nothing else!
I expect the winter vacation concept to be a game pack for next year, based on the timing of when the survey that talked about it came out.
My best guess for this one is either something else we've never seen before, or a grouping of some of the missing occults (werewolves, fairies, zombies, etc).
What I would like for an Expansion (because I'd prefer werewolves in a game pack with the detail of vampires) would be a sequel to GTW that lets me own bars/nightclubs and hair salons and maybe has some more active careers like a factory or construction job.