So what's going to be explanation for why only Galar and Kanto mons have Gigantamax forms?
What was even the explanation for why only Alola and Kanto pokémon had exclusive Z-moves anyway? Alola forms going only for Kanto pokémon had the in-universe excuse of Kanto being somewhat close to Alola, but for Z-moves I don't think they even bothered coming up with an explanation for the pandering. I bet it's going to be the same for the KANTOOOOO Gigantamax.