In Gen 9 Sinnoh and Johto are being referenced quite heavily, right? Sinnoh makes sense cuz BDSP and Legends Arceus were released in the same timeframe/Gen, but Johto is a bit strange. I doubt we'll get another straight-up remake since HGSS exists, but a spinoff that has us look at the region from a new perspective would be pretty cool. That is also what I'm mainly anticipating being announced as the only major new game for this year (I only say major because they could always come out with some random new mobile game).
This might seem weird to say, and I know lots of people seem to think BW remakes are on the horizon, but I disagree, I'm thinking 2025. First off, since Gen 6 there's been a two-year period where no mainline games are released, and if SV came out in 2022, Gen 10 should be in 2025. This also coincides with SV wrapping up its DLC and by extension its narrative more recently. Now, why is this important? Because I believe they would want the remakes to line up with the launch of the next mainline game. I get that BDSP launched in 2021, but the overall Sinnoh content extended into early 2022 with Legends. I feel like the reason they decided to go for a holiday game and a game placed in 2022 was because they had 2 games, so they didn't have to give up one or the other. Assuming that Gen 5 will just have remakes and not some other spin-off (so far Legends is the exception, not the rule) I'm assuming it should be around 2025.
Now that we've got my actual prediction out of the way, my wildcard prediction would be another revival of a spin-off Pokemon that hasn't touched in a while. New Pokemon Snap seemed to do pretty well, and there are plenty of other games itching for that treatment. Now, given that New Snap already exists as a revival they could keep it going with another installment (same thing more Mystery Dungeon but it seems to be in a weird spot rn, so I wouldn't bet on it), but I think they would want to keep innovating.
Rather than close off normally, here's a Pokemon main-line game tier list