What I think is interesting and not talked about in the copilot cases is there is actually two different copyright actions that come from using it.

The first is if GitHub had a license to distribute the code they have learned on. This is assuming that the code it produces is a derivative, which I don't think would be much of a stretch. For this I think most of the licenses that are used, GPL MIT etc, allow for someone to distribute in such a way.

The second is the user of copilot. They would be getting and distributing code where they wouldn't know the original license, but that wouldn't be a viable defense of infringement. To actually comply with most licenses they would have to follow the requirements.

In both cases I don't know if a fair use would really apply. Maybe GitHub could stretch the research aspect, but if you just use the code in your product there is no fair use.