This is probably right. LLMs can be used as a replacement for people (well, almost), or it can be used as a tool for people. Where that line is will be crucial.
I also don’t think it’s the same kind of “”“AI”“” as the kind that would be used to recreate a person’s likeness. That’s almost certainly going to be covered under copyright. (I bring this up because the article mentions it).
And even if there somehow is no line and any script written even partially by an AI cannot be copyrighted (unlikely I think) then the resulting film is still eligible for copyright protections.