I only just found out about it and was going to all his handles to find the same. I hope he just went quiet as he finishes the game to make Nintendo think he gave up or something. But I suspect you're right.
What I dream of, though, is that they took one look at the project and signed him on to make it for real... Oh well.
EDIT: That being said, this itch.io project is still marked as "In Development" so he either quit and forgot to change that or he's still working on it and just not active on his socials. That could either be to go stealth mode on Nintendo's lawyers while they're busy with Pal World, or maybe he DID get a contract with Nintendo... now I really am dreaming. lol