Just saw this in the 1.3 patch notes on the PTS forum
•Immunity granted by Break Free and the immunity given to you after you’re hit by a crowd control ability now provide immunity to all types of crowd control.
Ok so I can understand why this might be an issue in PvP. Lots of people firing off lots of different types of CC can mean you are stun locked.
But again this is a change that is meant to help PvP but is very damaging to PvE.
Having CC's on you bar to be able to lock down a mob has a cost. Its taking up slots on your bar but if it gives you the ability to follow up say a stun with a root or a slow its often worth it. This is just removing another level of depth to the PvE combat to cater for PvP.