A law like this would obviously need some sort of sensible definition of what "AI" means in this context. Online translation tools also use ML models and even systems to unlock your device with your face do, so classifying all of that as "AI contributions" would make the definition completely useless.

I assume the OP was talking about things like LLMs and diffusion models which one could definitely single out for regulatory purposes. At the end of the day I don't think it would ever be realistically possible to have a law like this anyway, at least not one that wouldn't come with a bunch of ambiguity that would need to be resolved in court.