And now it was just confirmed by Microsoft themselves :https://news.microsoft.com/2018/06/04/microsoft-to-acquire-github-for-7-5-billion/
They said that they will still maintain the choice of operating systems and the openness.
However, they haven't answered concerns about anything else...
Honestly, the so-called "IT" people with "real" jobs i've met so far don't care about privacy & security because they all put their faith on one company. Seems like unthinkable for them to run their own instances, even if they have the budget to do so.