What? No. Prior it meant Github was violating your license. Just because they were already doing it doesn't mean they had a right to do so. Now, it means you're

What? No. Prior it meant Github was violating your license. Just because they were already doing it doesn't mean they had a right to do so. Now, it means you're granting them a license. I'm not a lawyer, and I have absolutely no clue if it's even legal for Github to change their ToS like this. But I assume if you don't have the right to grant this attribution exception to Github (because you don't own all the code) and you don't remove your code from Github, then you are now also in violation of the rights of contributors to the project that didn't consent to this waiver.