public domain code can’t really be released under the GPL
Disney created films based on old fairy tales. Disney has a copyright on those films even though they include elements from the public domain because the films also include the artists' original expression. The linux kernel (probably) contains public domain AI-generated code alongside original work from its many contributors. If you wanted to get the entire project into the public domain, you'd have to get permission from nearly all its contributors or wait for their copyright term to expire. The small snippets of code which were AI-generated are public domain. The bulk of the project isn't, and the project as a whole isn't.
As much as I dislike AI, I can't say I understand forbidding AI-generated contributions on the grounds that the submitted code is public domain. I suppose somebody can come along and "steal" the public domain snippets, but I suspect it's difficult to definitively tell apart the human-written code from AI-generated and strip out the human-written bits. If they do, what's the issue? It wasn't yours to begin with and you can still keep it in your project. Moreover, now that the magical plagiarism machines exist, who's going to be lifting code in this way, anyway?
I came across the paper planes entry from the "See also" section in the atmospheric entry article.
Fun facts I learned: roughly the probability at least one person currently alive have been or will be struck by falling space debris from reentering satellites is 1% and 3% of the matter which enters the atmosphere is from satellites compared to meteors.