sure, no "court" should render it, but then

>AI output should be treated like a forgery

Who's passing this judgement this? Author? Civil society?

A forgery isn't a subjective assessment. A forgery is intentionally made inaccurate claim of the origin of something. If the by-line is claiming it was made by someone who didn't make it, it's a forgery no matter how good of a copy it is judged to be.