The SMN Job line from 50 to 60 delved more into the nature of the Ascians, specifically the revelation that lower ranked Ascians cannot endlessly revive if their host dies, as unlike the Overlord Ascians like Lahabrea, lower rank Ascians use the recently dead as their hosts, which means if their host is completely destroyed and there is not another corpse nearby to have their spirit flee to, they die too permanently (they cannot wait it out on the boundary of the 'aetherial sea').

Also in reverse in Stormblood in a blink and you'll miss it scene during the cutscenes to liberate Doma Castle, Oboro from the NIN quests is seen beside Alphinaud and Alisiae when they deactivate the magitek field generators. I have no idea if he shows up if you haven't at least done the level 30-60 NIN quests by that point though.