I found that out when I first got my rank, but I didn't really think anything of it. I hope they do get this fixed though, but it is possible it has to do with people doing /back to pvp.
I think if they added a new pvp then it wouldn't feel the same. If they added a new pvp arena though it should be a huge roman coliseum type build; it would be nice looking and maybe used more for people who want close combat pvp.