The patch notes said you shouldn't get a Toxicrene in the ebony void crusade panic room mission any more, but one spawned for me just now. It killed the NPC when it died so I failed the mission. :(
The void crusade was only started yesterday (Sat 10th Aug), so it was definitely after the patch.
It wasn't in the final room. It was in the one before that - the first elite you encounter after picking up the NPC.