[hnfong]

I think there's a lot of confusion about what records are needed presumably due to lack of understanding of what the law requires for proof of ownership.

Generally the party asserting ownership has the burden of proof. The standard is "preponderance of the evidence", which generally is understood to mean "more likely than not" or "> 50%". So basically it means if you can prove to judge or jury that there's a >50% chance you own the work, it's good enough.

Also note that in many cases where there's a dispute over the evidence, witnesses are summoned to testify. So you might not have a "full notary log" of how it was produced or all the "intermediate artifacts", but as long as the artist is able to convincingly explain how the work was created, and the other party's lawyers are not able to poke holes in their story during cross evidence, that's usually enough.

Which is, basically, what happens today, if the authorship or ownership of a work is disputed.

That said, I'm not sure whether "assume work AI (thus uncopyrightable) unless proven otherwise" should be the default for other reasons. For one, most quality "AI art" needs some manual adjustments or touch ups, and arguably the prompt and hyperparameters may be sufficient creativity element. I mean, that's basically how copyrights dealt with photography (the mere fact you decided when and where to point the camera with what settings is sufficient for copyright to subsist in a photo).