It seems that Copilot could address this issue by searching for matches in its source repositories for the strings it generates, with appropriate criteria, and

It seems that Copilot could address this issue by searching for matches in its source repositories for the strings it generates, with appropriate criteria, and give the user a link describing the origin of the code, who wrote it, and what the license is for cases where a match length exceeds a threshold. So, you wouldn't just get the Quake fast integer square root routine, you'd get a pointer to the Quake repository and license info from which it came. A separate model could be trained up that would find the closest match in source code repositories. A user could then use Copilot safely, attribute code correctly, and avoid code with incompatible licenses. This would be a better approach than "shut it down".