Just so you know, the Hearthstone one I believe is pure crap. I've opened up over a hundred or so and never once saw a legendary. Only legendary I have is Tirion and only saw him because of the Welcome bundle's guaranteed. Yes, they were all the same packs.
As for the other, I know after 2-3 months on the beta doing Emissaries every day running daily heroic dungeon and such never saw a legendary. So far it's the same streak on live.