If a mirror exists somewhere of course there’s an arrangement, be it CF or any other mirror. Now you’ll spin the meaning of the word arrangement right? Agreement is a synonym. the details are in the public view, as you’ve read in the links in Suddenly Sickness Feels, Cloudflare, really F-Droid?
Maybe CF has edge nodes in the “peoples” country or continent, maybe that helps them, dunno, people should make their own research too.
Adding a mirror to F-Droid? In Settings - Repos - press the title bar Plus icon… write mirror address.