This seems like a really, really easy problem to fix.

It should be easy to check Copilot's output to make sure it's not copied verbatim from a GPL project. Colleges already have software that does this to detect plagiarism.

If it's a match, just ask GPT to refactor it. That's what humans do when they want to copy stuff they aren't allowed to copy, they paraphrase it or change the style while keeping the content.