There was a huge shitpost about this on the subreddit. It's stupid to care. A hero went from full health to 0 in a single turn. The words "one turn kill" are met.

Sure, it's stupid to call something like bloodlust or double roar on a full board an OTK, which is why those posts will get downvoted. Just let them get downvoted for being boring/uninteresting content.

Look at the state of one turn kill options in hearthstone: there's not much there, and they require 10 or more mana. One I can think of is stormwind knight, PWSx2, divine spiritx2, coin, inner fire. But even that "relies on board state" requiring opponent to not taunt, unless you also include silence for 0 which is 8 cards. Another is malygos ancestors call shaman, which can pull off an OTK. That requires HUGE setup though, since you need to clear your hand of all other minions or someone on reddit will complain that it relied on rng and therefor doesn't count. There's also a mage burst down that doesn't require thaurissan too, using double sorceress, frost bolts, ice lances, fireballs and thalnos/kobold.

These are all late game high card combos too the "require" card draw that didn't happen in one turn. They technically relied on the randomness of card draw for the game, and the only way to guarantee the combo is to empty your deck. Since they're late game combos, you essentially also have to roll the dice on not being matched with face hunter or another aggressive deck. Totally not all completed in one turn.

There are technicalities everywhere, and thaurissan makes for really exciting combos that can't be done without him. Combos like this one which haven't been posted before, in which the opponent was killed in a single turn through tedious preparation such as card draw, removing opponent threats so you don't die too soon, drawing dream with ysera to remove a taunt, and protecting thaurissan for multiple turns. Setup is setup. Whether it was arcane intellects, a previous ysera, or thaurissan. The kill happened in one turn.