I don't really understand why would a domain change make manga uploaded before the whole ordeal unavailable, don't you just make the new domain name point to the server's IP? or are you changing servers too?
Also is mangadex hosted on a rented VPS or does someone from the team have servers at home or something?
I'm really intersted in the process so if someone has time could you explain?
edit: So I read up on what cloudflare does, and if I understand it correctly, switching CDNs shouldn't take that much time either, because -- I assume -- only the reader and the "infrastructure" of the website should be on those servers, and the real content would come from image servers, which would still stay the same.