You should not concede automatically against warlock playing Priest as this match-up is better for Priest than few weeks ago.
Besides I player against Warlock today which copied Tickatus twice and played all 3. And still lost. Let him have his fun now and then, without Tickatus Warlock will be total garbage.
He already is and Team 5 is doing it 100% on purpose. They removed all his power cards (Doomguard, Power Overwhelming, Soulfire). Gave him some useless buffs (Archwitch Willow, Deck of Chaos, Fiendish Circle) to pretend they care, but those buffs changed nothing. And they keep printing him the worst class cards of all classes, not even trying to address his biggest flaws and shortcomings. You don't even need to play test anything to see, that Warlock has no tools to compete with the meta (either as aggro, either as control or midrange). It's all too much to be accidental.
Probably it's because at least one class at any given time must be garbage (to add more "dead cards" to the pool and sell more packs). And since people like to play Warlock even when he's very weak, Team 5 just keep him in that state for profit. Class is bad for very long time now, but until last patch it still had decent play rate.