I don't think (and hope with all my heart) priest will be tier1 king of all the decks. It just doesn't have enough draw to reliably beat strong decks like highlander hunter.
Also, Scavenger's Ingenuity was pretty busted as a 2 mana card. Just compare it with Call to Adventure. You pay 1 less mana and get +1+1? That difference is just completely bonkers. I never understood how they printed the card with +3+3 in the first place.
And while the card itself is already alot better, the synergies are also alot better. Getting charge minions, rush minions, deathrattle (porcupine) minions,... when you think about it, it shouldn't be a problem to see the card was busted with +3+3.