More than an intended difficulty addition, since the last patch, it really seems as if some regular spawns have been replaced by packs of crushers, bulwarks, maulers or ragers in unnatural seeming clumps. Additionally, the same specialists spawn in dense waves, sometimes even on the very same location.
This occurs both on Auric and regular type missions on Damnation difficulty, with or without modifiers.
Not a bug, intended, AI director was ramped up to be more aggressive and difficult, specifically on the harder difficulties and especially maelstrom, this is in the patch notes;
“Increased the rate in which the conflict director ramps up difficulty on higher difficulties, mainly on Maelstrom missions.”