There is no "AT Proto server" - https://overreacted.io/there-are-no-instances-in-atproto/
People really do ask where "The AT Proto server is" as evidenced by this thread, and the really is no "AT Proto server" or "instance". AT Proto and BlueSky are a collection of services with no 1-1 relationship to a Mastodon or RSS server.
There's absolutely nothing misleading about that.