> That such scripts would be ineligible for copyright protection seems like it would be a significant issue.

Only if there is zero human interaction beyond prompting. And even that is just the Cooyright Office’s opinion of the law, not necessarily the actual law. [0]

[0] Which would normally be significant, because of Chevron deference, but with the increasing expectation that the Supreme Court will toss Chevron deference in a current case...