Once again, main predictions are that Mario gets one last spin-off title. I am personally hoping for Baseball to complete the main 4, but it might be Party.
Pokémon Legends Z-A gets shown off some more.
Finally a B-series series, likely Kirby or Fire Emblem, gets one last game to end things off. FE does have rumors for a completely new entry and a 4 remake.
On the 3rd party side, RPGs galore. Would guess we get Nier Replicant to complete the duo-logy. Also predict there to be one last “cannot believe this is on Switch title”. FF7R would be a decent prediction for that last part.
Biggest potential reveal would be Prime 4, though I have a feeling that got booted to Switch 2, so unless cross-gen it will not appear.