I would not hold your breath on RDM being a DPS/TANK, if SE decided to put this Job/Class into the game I fear the threads that will come out on the forum:-

"RIP RDM"
"you broke RDM"

need i continue

RDM on ffxi was know to be "Jack of all Trades, master of enfeebling"
sadly on FFXIV, enfeebling are next to useless unless there is some big changes to FFXIV
and whatever changes SE decides to make to RDM to make it fit in it will not be right by the community.