Except there are a lot of OSS and side projects hosted on github. It will take a long time for these to find their backups and move to another service. And some will lose source code due to faulty or outdated backups.
When you do a git clone you should always have a copy of the whole git on your dev computer so I am not sure why they would have to look for their backups.
Many rely on Github for more than source control hosting and issues. It's really not a non-issue.
I would like to have some basic issue tracking in git like in fossil (www.fossil-scm.org if you don't know, by the creator of sqlite). It's a shame that git has eclipsed all other options.
There are a lot of projects that use github-pages for hosting the main site and documentation, as well as fairly tight links with continuous integration/release pipelines.
I don't necessarily think this is a bad thing, but it is a valid concern.
A an enterprise Github subscriber, we would lose user authentication and authorization.
Fair enough but dont other github alternatives provide that?
And your wiki, and all links leading to your project and all tooling you've built around.
No idea about the other things, but the wiki is just an additional git repo that you can check out like any other one.
And then you still need the infrastructure to run it on a site where contributors already have an account or don't mind the extra burden of registration.
People moved away from sf fast enough im pretty sure the same thing would occur if things turn sour for github.