it's more complicated, the ruling was that AI can't be an author and the thing in question is (de-facto) public domain because it has no author in context of the "dev" claim it was fully build by AI

but AI assisted code has an author and claiming it's AI assisted even if it is fully AI build is trivial (if you don't make it public that you didn't do anything)

also some countries have laws which treat it like a tool in the sense that the one who used it is the author by default AFIK