That rumor from when the game launched was debunked

Copying some textures wouldn't lead to a patent lawsuit.

Unless it is a design patent, though I have no idea if Japanese law even supports this kind of IP protection.

Indeed Japan does: https://www.j-platpat.inpit.go.jp/d0100

That's simply untrue.

Sure, use some Pokémon as placeholders during development, but, No one even bothered to dedicate an employee to preventing those assets from getting shipped?? Gamers already had their fun, too bad for any investors that they didn’t cover their bases

The developers did not use Pokémon models. This was shown to be untrue.