I can buy that. Works for full Alolan lines too. Kinda sucks that we can't have regular Pokémons without transferring though.
I would honestly bet money there will be at least one NPC that will offer to trade their Regular Form Pokemon for the native Alolan version. "Hi! I just moved here from Johto. Would you like to trade your Alolan Meowth for my Meowth?"
Maybe only in post-game though.