Naxxramas: Necroknight's Deathrattle sometimes fails to kill minions correctly

[Jetz72]

Reported by srd_27 on the HearthSim Discord:

Had a weird bug yesterday regarding two Necroknights (Naxx minion with deathrattle of "Destroy friendly adjacent minions"). When one of enemy's Necroknight doesn't kill an adjacent Necroknight

Don't know why this happen. I've been playing lots of Naxxramas recently and had plenty of examples of Necroknight killing other Necroknights as intended

https://clips.twitch.tv/ColdbloodedColorfulDoveBrainSlug

(Clip shows an enemy board with 4 minions, the rightmost two being unsilenced Necroknights. The far right one attacks and dies. The one adjacent to it is not killed by its Deathrattle. It then attacks and dies, killing the next minion in line normally.)

On the turn before that twitch clip, she put a Undertaker in between the two Necroknights. And she traded the Undertaker into my taunted Mech, while not with the Necroknight.

Cause is unclear, but Blizzard may be changing up the implementation of positional Deathrattles. To my knowledge (which may already be outdated as of this issue), Necroknight is currently the only one they've tried, and its effect doesn't work intuitively when the board changes more drastically due to multiple deaths and Deathrattles.

Full game here: https://www.twitch.tv/videos/688414250?t=02h03m00s