I guess it's expected when a product moves faster that it breaks a little more often (and since I use it a lot, I have many occasions to be there at the wrong time), so I'm not worried [yet] and am just glad we get new features.
Obviously for this to work it needs two elements:
1. A format or standard that multiple vendors provide and Microsoft implements
2. The other vendors being unable to keep up with any Microsoft extensions
None of the above apply to GitHub. The first part could apply to Git itself, but Microsoft has nothing to gain by doing that as the second part would be very difficult. EEE worked largely because Microsoft's competitors were companies with limited resources and programmers, but it doesn't work when any programmer and company can help keep up with them - see how they failed to apply it with HTML despite trying very hard. Also EEE really relies on network effects (the last E comes because people flock to MS products) and they already have a better network effect with GitHub's social aspect, they do not need to try and manufacture one.