They said the same thing at WoD, so yes it is like WoD.
You must be new?
That said, viable does not = OP/better than DPS counterpart.
Letting wishful thinking get the best of you!
- - - Updated - - -
"Tanks in PvP
Finally, we have the topic of tanks in PvP. Apart from a few niche cases like flag carrying; tanks have been intentionally non-viable in serious PvP for several expansions now. The reason for this was simple: fighting against tanks was very frustrating, not fun. They were near-invincible, had numerous CC abilities (primary stuns), but did little enough damage to not be able to kill you (in most cases, anyway). By excluding them from PvP, we preserved the enjoyment of the rest of the playerbase. However, that has the obvious downside that people who prefer to play tanks are excluded from doing so in PvP.
We decided that we could do better, and satisfy everyone involved. Our other changes to tanks in Warlords of Draenor got us most of the way there. Tanks’ damage will already be tuned to be somewhat weaker than damage dealers, but not trivial. We’ve already removed the additional CC that they had during the CC Disarmament and Ability Pruning. All that remains that makes them frustrating to fight against is their invincibility. So, we’re causing tanks to take increased damage in PvP, so that the net result is that they both deal and take somewhat less damage than damage dealers.
Tanks now take 25% additional damage while engaged in PvP combat."
https://worldofwarcraft.com/en-us/news/13423478
-From WoD
They are trying it again with legion, they will not stay at the OP level they are at. That is a fact