So sorry for such a late reply, been a bit occupied.
@~Nilion~ I think evolutions after Kanto are fine, such as Golbat being able to evolve into Crobat. However, younger evolutions, say Pichu’s being the predecessors to Pikachu’s, would not be found in the Kanto region. And the Kanto Pokédex would still only have 151 Pokémon, later Gen evolutions would simply count as an entry to a different dex.
Also, all types exist as of the latest release, including fairy types and the like.