The Hate Mini Bosses should be in game at the start of the epics:
The listing
Coercer T'vala
Grandmaster R'Tal
Going by my research it also appears that within a month or so (wayback dating does make this difficult) after the epics came out they were starting to drop Inny loot items: Rakusha Cloak, Shattered Emerald plus Rods of Infinite thought.