"no matter what license you use, you give GitHub the right to host your code and to use your code to improve their products and features" I contribute my code

"no matter what license you use, you give GitHub the right to host your code and to use your code to improve their products and features" I contribute my code to X project outside of github (say on a mailing list) under the explicit understand that my code is under GPL (say GPLv3 to be specific). If someone later uploads my code to github and github uses my code to train their ML model in violation of GPLv3 isn't the point that the person who uploaded my code to github is in violation of GPL by giving it to someone else under less restrictive terms? Does this mean that the github terms of service are perhaps fundamentally incompatible with uploading copyleft-style (or perhaps specifically only GPLv3 level) restrictive licenses? And, if so, probably they always were but nobody cared until now.