Tip - there is a "deleted repos" section in GitHub UI where they will appear, apparently with an option to restore them.
In short - all I said seems to have been nonsense. Apologies!
Still, the main issue was the process how they handled it. Your build breaks. This is how we found out.
No recourse for such decisions unless you make a stink about it on an orange website or get enough likes on the website with the blue bird logo.
Furthermore, no: GitHub has a history of being bad at this kind of thing:
https://news.ycombinator.com/item?id=22593595
From the linked article: "A week after I’ve opened the support ticket, GitHub has finally replied. Suspiciously, this happened right after someone important has posted a link to this article on Hacker News"
https://news.ycombinator.com/item?id=22628961
Top comment: GitHub CEO coming in and apologising. From the linked tweet: "You sited US trade sanctions and sent me a non-descriptive email with no remediation information".
Clearly not that irrelevant if you're in here commenting.