If that's mandatory, I don't think I would come back. I never got hacked, because my password is strong enough. That would a real pain for me.
Nothing is mandatory, so I don't think 2FA will be mandatory. It will be just a choice , like hide an e-mail or reveal it.... and like always 'you can always leave' (
https://www.youtube.com/watch?v=fasTSY-dB-s).