The subject matter of an MMO may be serious, but there are always plenty of players who just want to play the game and have fun with other people. Part of having fun with other people is interacting with silly emotes. 
 
Warhammer 40,000, on the other hand, never winks at the camera. No hidden jokes. It is serious business. Orks are the bizarre exception to the otherwise universal rule. 
 
So with the Dark Millennium on the horizon, the question becomes: if I role an Astartes, will I be able to /dance?

I'm gonna guess no on this one. 40,000 treats itself with the utmost seriousness and rarely ever cracks a joke, not that that's necessarily a bad thing.

I can all too easily see Chaos players headbanging and thrashing about as an emote.

I hope not. Orks aside, I like my Warhammer self-serious.

" I hope not. Orks aside, I like my Warhammer self-serious. "

I say yes to /dance