The broken interaction between Thrall, Deathseer and Unlicensed Apothecary will be fixed in an upcoming patch. The news was confirmed by Hearthstone designer Mike Donais in a short post over at the long-running Reddit thread about the problem.
If you're unfamiliar with this particular interaction, it comes about as a result of playing Thrall, Deathseer onto a board where you have at least some kind of minion presence. This Death Knight card automatically evolves those minions when he's played, a process which transforms them into randomly chosen creatures that cost two Mana more than the original character.
There's a problem if one of those cards is transformed into Unlicensed Apothecary though. This character dishes out five points of damage to your hero for each minion that's summoned, and these transformations count as summons! The end result is very often a game-ending volley of self-inflicted damage, and the interaction is not considered to be working as intended.
While undoubtedly amusing for the opponent, this interaction is not much fun to be on the losing end of. It's particularly problematic too given that Evolve Shaman - which inevitably includes this powerful thematic card - is more or less the hero's only truly competitive archetype at this stage of the Frozen Throne meta.
Donais's response to the ongoing community discussion was reassuringly straight to the point though.
“The Thrall interaction should be fixed in the next patch,” he posted. “The first big patch since Thrall's release.”
When exactly this fix will appear is unclear at the moment, although it seems likely we'll see it go live when the next monthly card back is added to the game.
We'll post an update to the home page as soon as a date is confirmed by Blizzard.