In future games, if we start finding alolan form pokemon in other regions, would they cease to be considered alolan forms? I mean it could be wiped away with an “oh i brought these pokemon from alola, and then they escaped into the wild” explanation. But still..what are your thoughts?
Well, I think probably the most likely scenario is that we just won’t find Alolan form Pokémon in other regions without a good reason for how they got there. Several of the Alolan regional variants have some sort of “backstory” for why they exist in Alola specifically, like Rattata, and Raichu’s Pokédex entry explicitly says that Pikachu evolve into Alolan Raichu only in Alola, but not all of them do, so it’s plausible that some of them could have originated in other regions with similar conditions and spread to Alola, or vice versa. Circumstances could very well be different for each species. For some of them the idea that they are regional variations, that they exist in some parts of the world and not others, is more important than the idea that they are specifically Alolan.