30min debuff is all fine and dandy, but what if you want to run another heroic and the first one took only 15min? do you now have to sit around for 15min before you can Q again? does the "debuff" get removed when you kill the last boss? what about putting in a fix so the debuff could be removed if say your tank decides that they "don't want to tank HoS again", and drops group, and you're group sits around at the front of the instance for another 10min waiting for another tank to be added to your group, just for That tank to also not want to tank it and drops group. so then your healer says "F*@K this", and leaves. now you have the choice of leaving with 20ish min left of debuff or sit around and wait for both a healer and a tank, that may or may not stick around. can they put in an option to 'vote to disband the group' and removing the debuff if the group officially disbands?

Ain't gonna stop me, man, screw Azjol.

Read the patch notes. The cooldown for the debuff starts when you leave the group and the dungeon finder is no longer a debuff. If you complete the dungeon and you do it in 15mins or more, you can queue up right away like you can now. If you drop group, you have to wait 30mins

Check the notes, the cooldown on finding a group is still 15 minutes. The only time you have to wait half an hour is if you actually drop group before the dungeon ends.