Big enterprises are on a different github deployment, so I doubt they are affected by this
- The cloud-hosted service presumably on slightly different infra,
- The self-hosted version of GitHub that runs on hardware you own.
The second definitely counts as "real" self-hosting.
(maybe F500 people have their colocated box, but I have the impression that those are the "first class" seats (very expensive but _very few_) whereas enterprise cloud is the "business class" (loooooots of seats making a lot of money)
Depends, some of them use GH Enterprise but many (surprisingly) don't.