Love the new tavern brawl, as I get to test drive the decks hadn't crafted yet. However, it proved to me once and for all how absolutely, stupidly broken the rogue quest is. 1st time I've ever played it and I managed to finish the quest AND prep it out on turn four. Killed mirror opponent on TURN 5! That is stupid. STUPID!
There is a clear difference between strong and straitghforward. I remember when Old Gods first launched, the C´Thun Druid was all the rage on the first week, because the natural ramping Druid gameplay, together with the Dark Arakoa, made the deck simple to put together. The C´Thun Warrior, even having a similar gameplan than an already established deck (Control Warrior) took longer to be figured out, but was the most enduring C´Thun achetipe.
Regarding the quest rogue, the "start in hand" mechanic makes it very easy to build a deck around quests, and the effect of the quest prizes a deck that requires little thinking to put together to a "good enought" effect. This is simmilar to zoolock, a deck that uses an always-avaiable resource (hero power) to make the best out of simple and cheap cards (most common and rares). It might require incredible deckbuilding skill to have the perfect quest rogue or perfect zoolock, but a "playable" version is easy to buildand to tweek according to the meta.
The straightforward deckbuilding and always-avaiable resource are only enphasized by the brawl: recipies are suposed to be not-perfect versions of archetipes, to encourage the community to go trought the perfecting process. This creates a huge advantage for simpler decks, in this case, quest rogue in this brawl.
Quest Rogue is a powerfull deck, which might stay on T1 across the year, but I don´t think that is a sure given at the moment, regarding constructed ladder. Let´s wait and see.
There's already a tech'd version with Bilefin Tidehunter and/or Glacial Shard that slows down pirate warrior a whole lot. Plus every deck is running the new crab, making pirate warrior much worse and far less common.