No red lights, so it's probably not something catastrophic like that facebook DNS SNAFU, but it definitely smells infrastructure- or deployment-scoped. Like either small DNS issue, or some load balancers are sending traffic to servers which cannot handle it programmatically (schema change?) so they are barfing.
1) Is GitHub runing under Azure's technology stack?
2) Is GitHub under Azure's mamagement (in contrast to Visual Studio's team)?
I'm not sure about two but I'm pretty sure that GitHub doesn't run under Azure at all, considering that GitHub has fully separate networking from MSN's/Azure's (and GitHub's machines do pingback unlike most of Microsoft's machines which don't).
Huh? As of at least 2017 GitHub was running their own data centers [1]. Any evidence that’s changed? Microsoft bought them in 2018, I can’t imagine they went to AWS after that.
[1]: https://github.blog/2017-10-12-evolution-of-our-data-centers...