If I recall correctly when they announced the role quests they said they'd be for melee physical, ranged physical and magic DPS. Currently though, the DPS sub-roles are called melee DPS, physical ranged DPS and magic ranged DPS.
It could be nothing, likely is, but adding that physical qualifier to the melee and dropping the ranged one from magic while adding a voidsent summoning melee job.
I wouldn't say I'm set on the theory yet, but maybe Reaper will be classed as a Magic DPS, and get Magic role actions like swiftcast as a result.
Alternatively maybe I'm reading too much into how they phrased the role quest confirmation and nothing changes DPS sub-role wise. They could just give it a rez that works differently though, no real reason it couldn't be an instant or quick cast on a long cooldown for example.