They used to have a (low) chance of dropping Celestial Lotus. Now, after my latest run on Elite, I had one drop a Tainted Brian Matter and the other a Manticore Eye? Did they eat some Aetherials and Manticores in their hunger? 
probably not related to lore. crate might just want players to get more craft materials from their morgoneth dungeon runs to compensate the rng for the magi spawn chances.
I was joking about lore relations, but then why doesn’t Grimtools show this? I am level 97 - the monster loot table only shows Celestial Lotus and the Morgoneth set parts as potential loot.
I did a few Morgo dungeon runs in recent days. Scions only dropped me one or two lotuses. And this dungeon was out for a year now, didn’t see any other mats drop from them. Only a vendor sells one rare mat per run.
No, they definitely drop other stuff too. Maybe it is only on non-ultimate, but they dropped random materials on my 2 runs. I don’t mean the vendor, these dropped from the Scions.