Given that you have to be pretty quick to trinket/bubble out of a rogue's opener/finisher, immunities count as a counter to Ret as well. Bubble, Turtle, Cloak/Vanish all work. Also, if the TV is required to finish, there's the solution used in LK too - don't let the Ret close.
BTW I've seen ferals delete people in their opening. Fire Mages in moments, from range while moving... There are plenty of specs that can just wipe people that don't have immunities or ways to drop combat and GTO. As with LK back in the day, if specs like Ret are nerfed now, once people have gear and more Vers (Resilience in LK of course), Ret will suck.