At first I thought I was just unlucky not to draft them, but after the 5th run with a DK that has 2x green and 1x blue and not getting a single plague card offered, I realized that Blizzard either removed them or decreased their chance of popping up immensely, so much, that they’re practically non-existent anymore.
This is really annoying because I spent 5 runs going for the required rune combination only to find out that I can only pick random stuff and play a broken deck.