>>58947877BDSP is mainline. Even if Game Freak didn't make it and even if it was JUST a previous game copy/pasted to a new engine instead of an enhanced remake, it's still considered the same as HGSS.
Pokopia won't be mainline, unless it's something akin to L: A and be time-displaced from the current era in the mainline games Like the far FAR future of Kanto), given its setting is "Kanto but all the humans fucked off years ago". Best bet is it's just a spin off (what if all the people fucked off from Kanto because reasons).
