I doubt iconic FF job names will be used for classes. The current system seems to be that classes are called something generic, whereas jobs are the iconic FF name for essentially the same thing. Gladiator to Paladin, Marauder to Warrior, etc. Bet on Thief being a job, if anything, but not a class.
Also, I'm not sure if RDM is really possible under the current system, since it's by definition a user of both white and black magics, with some fencing ability. How would it have both WHM and BLM spells, along with a sword? And if we went with the idea many suggest of just giving it enfeebling and magical blade attacks, then is it really even a RDM anymore, or just a Magic Knight with a rapier?