Isn't that how it always worked? I know on 16-man they enrage at 8 stacks. Everyone has an interrupt now so it should be even easier then before.
NO, it isn't, i have no idea how it works on 16M, but ive been killing Kephes HM 8M every Tuesday for the last 4? months, i think our first kephes kill was in May, you can believe me, we have the encounter mechanics mastered to the point were it has become boring and done while chating about how much we want a new operation (welcome TfB) or how much we like the new sci-fi film on theaters ....
Just go inside there and check by yourself, yesterday (just after 1.4 patch), Kephes encounter in HM 8M was working under a totally different mechanics.
Now, after some sleep, i have change my mind, i dont want it fixed back to its previous state, maybe a new loot and explanation on the silent change, but i want it to remain with the new and more challenging mechanic.