He made a twitter account a few days ago (linked on his itch profile) and stated
"Hey, I made this account to share my adult game projects.
Right now I'm working on Pokémon Naughty Version, an 18+ Pokémon parody.
I'll also use this account to look for artists, voice actors, and other collaborators for my projects."
What you've said about nintendo is not really a concern for someone doing such a niche project