Um, no. They are asking not to be trapped in perpetual limbo with a constant flow of new players who each have to learn the fight from scratch while you are way ahead of them. And please cut the crap about getting a set group. Its old, and doesn't actually address the the fact that DF random groups are mostly useless for extreme fights.
My own opinion? They should never have allowed people to sign up for those fights with random groups of people while leaving the learning curve so shallow through the leveling experience. SE should have made the last ten levels a much steeper curve than what they currently are so that new players are at least accustomed to hard battles by the time they reach end game.