"PvP trinkets now grant immunity to reapplication of an effect from the same spell cast when they break abilities with persistent effects, like Solar Beam."
So they will work like a buffed Nimble Brew, which grants 60% reduced CC effect
This is a really good change, and would/will stop long CC chains from the same class, i.e Mage Poly, Lock Fear, Druid Cyclone.
Like if you cri evritiem