Expanding on that, even if Microsoft sees the error of their ways and retrains copilot against permissively licensed source or with explicit opt-in, it may get trained on proprietary code the old version of copilot inserted into a permissively licensed project.

You would have to just hope that you can take down every instance of your code and keep it down, all while copilot keeps making more instances for the next version to train on and plagiarize.