Its not that grim. If you have open source project there, you have a license that allows others to use your code. License terms apply.
All my projects there have AGPL/LGPL license.
Private repos are obviously different. You can push GPL code there and there is no legal way for Microsoft/Github to get access to it
The issue seems that people are afraid that Microsoft is integrating everything to their ecosystem and removing all other options, ie allowing github api only from azure.