That is an opinion, but certainly isn't settled law in any jurisdiction. Indeed, the answer to whether some, all, or none of an LLM's output is ever copyrightable and under what terms is the billion dollar question.

A project that incorporates code with shaky legal foundation will find it tough to convince others to contribute, if it's possible one day that their contributions were in vain. The right answer would be to extricate such code upon discovery, like what OpenBSD had to do when the IPFilter license turned out to be incompatible with the project.