I had two times today in Uldaman where a damage dealer left early and, totally unlikely, there never came another one to fill up again, even though I specifically clicked the prompt to open a slot again.
This really sucks, especially because of the targeted gear farming that naturally occurs a lot.
Even worse: Just now the tank left after first boss! Then I had to tank and the rest of the group was inexperienced and I gave up, too, because I queued as damage and didn’t have the endurance for unprepared tanking with a weak group of 4.
Queues are so much quicker for tanks and healers, but leaving early for farming reasons is so much worse in those roles particularly when the queue refill doesn’t work for some reason.
Also, the estimate can be so very off. Dunno whether there’s a heavy penalty for multiple runs and maybe the ovccasional early leave even though there is no deserted penalty given, but it can say average wait time 3 minutes while I am in the queue for over half an hour, and even had a failed group composition during that.