>>36840275Porygon is made in Kanto, so it is by all technicalities a Kanto Pokémon, but it's not a Pokémon found in Kanto's ecosystem. It's only obtainable through the Rocket Game Corner, presumably through Silph Co.
I remember a line about "rare and exotic Pokémon" for the Safari Zone. To use your elephant example, you can have elephants in zoos and habitats in North America, but it doesn't make them native to North America. They also call it the safari game when you go to catch Pokémon there, so it's not presumably a real life safari like in Africa, but something that didn't always exist.
I would count other "non-natural" Pokémon like Grimer or Magneton as native to Kanto because they did technically become a species over time that populates certain areas. It's not like Porygon where it was intentionally created and doesn't exist in the wild or for most of the general public.
