Well, I had my first run in with the new 25 limit to aggro today and i wasn't even mass pulling like it was supposed to be for. This was during the AMY (Arch Magus Yozanni) event. I was in the middle of the event and lost my offtank due to a misheal on my part, so i just grabbed all the mobs with the MT and decided to plow through it and finish off Yozanni first before the adds since he was hitting the hardest. Had him down to about 18% when all of a sudden the MT was punted out of zone, took me a minute to realize what had happened because the tank was still full HP, no way he was one shot that quick.
This isn't a request to change the limit by any means, just wanted to give a heads up to anyone else who might be trying Yozanni soon and letting them know that this will end up happening. I know its not supposed to be an easy fight by any means, however when you have the ability to just tank the boss down while tanking the adds at the same time, you shouldn't be punished for it.