Lol just a joke play on the word "disabled" But to answer your question yes the dragon has been removed from all servers, this was becuase of all the arguments over the dragon eggs i think.
They are disabled. there were once Dragons but then JustinGuy and the rest of the staff decided to kill them as they seem to cause problems + could ruin the xp leaderboards and take an arrow to the knee for the economy
People were "fighting" them on all the servers. I suggest you take a look at this thread: http://empireminecraft.com/threads/mobs-back-in-town-protect-your-things.6116/