I really like all of these suggestions, and would just request that, in the same way as current worlds are reminiscent of real places but also not, that these vacation destinations also be Simified versions that are not actually France and Italy by name, but evocative of them. That would mean giving up having exact depictions of real-world landmarks, but I could imagine fictional versions that would be creative and interesting instead. The main reason I say this is because I think it makes sense for The Sims to be its own world, and not to suggest (any more than has already been done) that there is a 'real world' that exists alongside it. I know there are references to various real countries in item and food descriptions, but I've always taken those as more being for the benefit of players to know what something is supposed to reference. It works better, from the universe of the game, if all the places that exist in The Sims world just exist in that world, rather than trying to imagine that there is a SimNation and then a few countries over is real France, etc.
As far as other vacation destinations, I'll just echo what others have said and request continents and regions that we haven't seen yet (Middle East, Africa, Australia), as well as perhaps interstellar or time-travel-based destinations that are more fantastical.