Imagine managing a gitlab instances. You're doing it for years and have a stable environment. If one of the instance gets hammered by external traffic or one of your data center dies, will you call the gitlab devs to deal with it ?
Depending on the size of the deployment. (Not sure what you mean with "one of your data center" though) If it's just you, you deal with it. If you're running a bigger deployment, you likely have GitLab devs internally that will be reachable. Even bigger - you're likely to have access to upstream devs in the ultimate tier even with self hosting.
So... Yes, sometimes you will.