I think the author hasn't considered this: I believe Copilot is trained on not only OSS on GitHub but also proprietary software. In terms of reproduction by Copilot, Copilot is not licensed to distribute OSS without license just as it is not licensed to distribute proprietary software. To any extent that OSS authors have a case against Copilot, so too do proprietary software authors, and likely moreso. If there is indeed a case against Copilot reproducing code, I'd expect it to be championed by well-financed corporations foremost.
