God, the gen 9 trailer meme is the worst one I've seen yet. This isn't a capeshit movie or a KH game, Pokemon isn't known for that shit and it would feel so forced. They could drop some subtle hints with NPCs or items like they usually do, but that's it.
If gen 9 is coming this year, which is a huge if, then the earliest we'll see a trailer is the end of February.