That study is like giving a written test to an illiterate adult, seeing them do worse than a child and saying they aren't intelligent or innovative. Like I said earlier intelligence is multi-faceted, and chatgpt excels at rhetorical, conversational and other types of written intelligence. It does not, as that study shows, do well in spatial manipulation, that doesn't mean it's not intelligent. If you gave that same test to a paralyzed blind person with little to no concept of spatial reality they'd probably do just as bad. If you asked them to compose a short story or an essay they might be good at it because that's where they're capabilities lye. That short story could still be innovative in its composition and characters, and could be way better than anything a child wrote.

You have to measure different types of intelligence with different tests. If you asked chatgpt and a set of adults and children to write a short story about a wholey new subject chatgpt would beat most of the children and probably some of the adults.

And if that short story is about a new subject matter completey out of its training set what/who is it plagiarizing from? You could say it's taking common tropes, themes and story elements from other stories, but that's fundamentally what a lot of writing and culture is. If that's plagiarism then you should be more worried about the marvel franchise as it's a plagiarism machine that has way more cultural impact.