I noticed that the frequency of the drops for the cards listed in the special offer a few weeks ago for Neheb, ramanhup hydra, Lilliana's defeat and many others is still substantially high. My last 6 mythics were neheb and ramanhup hydra... 3 each. I've also received numerous dupes of the other cards in that same offer. If I didn't know any better, they have not turned off the increased draw ratio for these select cards.
4 weeks in, numerous HOU premium packs and boosters and I'm still hunting for a HOU mythic. this has been the worst dry spell in the history of the game for me.