IANAL but I'm pretty sure that's not how it works. If MS chooses to violate the original license that is between the original author and MS. You as the uploader

IANAL but I'm pretty sure that's not how it works. If MS chooses to violate the original license that is between the original author and MS. You as the uploader do not and cannot grant rights to MS which you did not receive in the first place. You upload the code under its original license and if MS does not honor the license that is not on you. Not defending MS here in any way, btw, I do firmly believe in opt-out.