Can a human even put GPL on bot written code since it relies on copyright to protect it? Is that like museums adding copyright to scans of public domain paintings in their holdings? Which was fought about in courts for years.
Probably a human could put a copyright on a prompt (that would be the "source" and the LLM would be a compiler or interpreter) and the generated code would be derivative of the prompt and any inputs.
It would probably get into whether the prompt itself is considered copyrightable. There is some threshold for that since I have heard some patches are considered insignificant and uncopyrightable.