I get it now

Since the Switch 2 is going to be backwards compatible with the Switch games, GameFreak plans to eventually make every single region available to play on that console (and also compatible with HOME)

>Kanto with LGPE
>Galar with SWSH
>Sinnoh with BDSP/PLA
>Paldea with SV
>Kalos with PLZ-A

So during the next 2-3 generations (released on the Switch 2) we should be getting
>a new Johto game
>Unova remakes/Legends
>a new Hoenn game
>Legends Alola