I journeyed into Old Kingdom for the first time in a long time last night to pay our dear friend Herald a visit. When I used MC/dismiss to remove the other players during Insanity, they did not vanish! I just burned them the old fashioned way after the first did not disappear after the MC did not work.
Has this been changed? I might have had an early break from damage before I successfully dismissed them, but I had feared the melee and was concentrating on the ranged when it happened.