Apparently, the Burning Legion is either as deadly and implacable as the army they are named for, or as false and tricky. Us.gorgonnash.info is now reporting them as having come from behind to unlock Phase 4 the first of all servers. Given that they are a PvP server, this would be an especially amazing show of determination and server togetherness.
However, given that, until only a few hours ago, they were only 37% according to the site, according to Trade chat on the Burning Legion server (Thanks, Zulama), and according to a poster on this thread, it seems more likely that someone tampered with their upload file to fool the site.
It's honestly rather disappointing that someone has decided to tamper with a trustworthy group effort like the gorgonnash.info website. I know we're all better than that. So to all of you who've been faithfully uploading legitimate info to the site, and to all of you who have been working hard to help your servers unlock each phase, I say congratulations, and thank you. Hopefully, one jerk from the Burning Legion server doesn't dampen our spirits.
Edit: Thanks to Unagieater of the Burning Legion server for confirming via screenshot in the comments that this is a hoax. The server is only about 41% complete with Phase 3 as of this edit.