One for the developers.

Regarding the new 20th completion mechanic for raids; If you run ADQ2 (for example) 19 times on a Heroic difficulty and once on an Epic difficulty will you be given a 20th named raid item reward or will you HAVE to run it either 20 times on an Epic difficulty OR 20 times on a Heroic difficulty and not a combination of the two?

Thanks in advance.