Game Freak should include every previous-gen Pokémon in every new Pokémon main game they make, while still adding over a hundred new Pokémon each gen and have the games be on top of that. They easily could and there is no excuse.

The dex cut was not inevitable and the amount effort to include all previous gen Pokémon does not scale with the amount of Pokémon. So none of this stupid idea that eventually they would have had to do it at some point.