In a previous job I managed a migration from bitbucket (!) to self-hosted Github Enterprize. As part of the migration I forced the creation of a monthly "backup restore test".

Every month we had a recipe to spin up a new instance of the Github appliance, and import the most recent backup into it.

A lot of systems do tend to get a little neglected over time, and of course different organizations have different priorities, but I insisted on this because I figured for that particular company the Github instance was one of the most critical components - if it is down people can't work.