Also I don't get why GitHub is fitting as a hoster? Because of git and the commit history?
Definitely not because of their strong believes in privacy as a company owned by microsoft...
Exactly for the commit history: we want to make our legal agreements, and any changes made to them, as transparent as possible, we thought GitHub was the most accessible place to do this
That's not really the point though: we have to notify our users of any changes to our legal agreements regardless. We are using GitHub to make these changes as transparent as possible. Because of such legal notifications it would be very obvious if such tampering was going on based on the effective dates of the policies. Again, we're being this transparent because we want to do everything we can to protect our users security and privacy.