I think this may need to be explored a bit more, because so far it's more of a conspiracy theory than actual trends. For starters, a lot of stuff has been added to TS4 already. The only things really missing that have been pretty core to previous games have been a Generations type of EP, along with other supernaturals like werewolves. So given that the missing stuff is getting more and more limited, it can be a pretty strong false positive to claim they're hinting at Generations when that's one of the few things left that people still want from older versions of the Sims. It's like if you put a ROYGBIV rainbow in a hat and had people pull colors out. If RYGBV come out already and you're up next to pull, you can greatly anticipate pulling an O because you know the list of potential picks has dropped dramatically. This doesn't mean that you're hinting at O coming nor does it even mean you're clairvoyant - if O and I are all that's left, that's all you have to anticipate pulling out of the hat.
The second thing is how much of an echo chamber the community can be. Relating to the point above, people will tend to anticipate and talk about stuff they're desperately wanting, and seeing as Generations is currently that flavor of the month, it's at the top of everyone's mind. Influencers will either consciously or unconsciously gravitate to this topic since it's popular, and they may even end up making builds or families with this kind of thing in mind. Again, it doesn't mean they're hinting at or revealing that Generations is coming, it can just mean that they're social creatures and their content is flowing with the current trend and mindset.
Another thing to go back and research is Snowy Escape if you believe that the Game Changers inadvertently hint about stuff. Snowy was really the first pack where there was heavy collaboration with influencers to do the builds and make the world, so if there was any pack that should have been inadvertently teased or hinted unconsciously, it would have been this one. Looking over the content prior to Snowy's release from the Changers who were part of this packs' world development should in theory show them trending towards this type of concept, since it would have been fresh on their minds since they created the onsens, Asian homes, and bars and such.
The major point is, it may feed into hype and raise expectations too high to promote this kind of theory without much trend analysis and evaluation. They could just as easily release a pack like farming or boarding school for all we know with the inclusion of bunk beds.
