To completely proove whether its gfed or not we would have to wait for it to drop, and if it drops to a 20, and has 24 lvl req, then you could say well you just have to farm it on a lvl 16 char, and then you could say, well you have to do it in dugeons, not open world.
I havent seen a pic of any ultra rare epics drop with lvl req below 21 after prepatch, but i still could be wrong.
p.s. My hdd with wow died, no testing on ptr until new arrives :c