IANAL, but it seems like inclusion in the data set and subsequent distribution without the copyright notice would be a violation.
I'd bet that this is enough to detect cases like GPL code, but I also bet that if this analysis fails instead of falling back to "unknown license, assume proprietary, don't copy" they fall back to "free lunch!". Because reasons.
Even though even permissive licenses like MIT and BSD require attribution and preservation of copyright notices. Maybe their AI just can't "reliably detect" licenses.
It’s the similar legal clauses used for decades on social and video hosting platforms.
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You grant us and our legal successors the right to store, archive, parse, and display Your Content, and make incidental copies, as necessary to provide the Service, including improving the Service over time. This license includes the right to do things like copy it to our database and make backups; show it to you and other users; parse it into a search index or otherwise analyze it on our servers; share it with other users; and perform it, in case Your Content is something like music or video.
This license does not grant GitHub the right to sell Your Content. It also does not grant GitHub the right to otherwise distribute or use Your Content outside of our provision of the Service, except that as part of the right to archive Your Content, GitHub may permit our partners to store and archive Your Content in public repositories in connection with the GitHub Arctic Code Vault and GitHub Archive Program.
Any User-Generated Content you post publicly, including issues, comments, and contributions to other Users' repositories, may be viewed by others. By setting your repositories to be viewed publicly, you agree to allow others to view and "fork" your repositories (this means that others may make their own copies of Content from your repositories in repositories they control).
If you set your pages and repositories to be viewed publicly, you grant each User of GitHub a nonexclusive, worldwide license to use, display, and perform Your Content through the GitHub Service and to reproduce Your Content solely on GitHub as permitted through GitHub's functionality (for example, through forking).
They don't even include training for copilot (though a dodgy lawyer will likely try to include that as "part of providing the service). 3rd parties only get a license to fork your repo, seemingly not even a license to do anything with that repo. (And hot take: Github should just let people disable the fork button already.)