>>41846354all Pokemon
another wild area or two. preferably no routes and just good wild areas (but that's not feasible with a pre-existing landscape)
B2W2-style timeskip story (Professor Hop, gym leader Marnie and Bede, retired Piers with his hair down, maybe turn Allister+Bea and Melony+Gordie into double battles, maybe follow up on the whole Kabu is from Hoenn and maybe related to Flannery thing, etc)
have an actual evil team this time preferably with dungeons or something where the rivals and such can get some character-building
B A T T L E F R O N T I E R, it makes perfect sense for a game with such a strong focus on like gym+sports.
new pokemon maybe? ORAS had new megas, USUM had new UBs, so SWSH2 should at least have new galar forms (I still want a Galar Golurk evo that's Steel/Ghost or something personally, and also different variations of the fossilmon)