You realize Miracle is pretty much already dead, yes? Not being played in high level tournaments. The best Miracle streamers have been fiddling with it for a couple of weeks and their rank goes down overall when they play it. Forsen has this new build where he dropped Shadowsteps and Leeroy, added in a Deckhand, Coldblood x2, and a Faceless for a 20 damage four card combo @8 mana. It was decent, he was still losing more than he was winning in legends. Ditto Malygos Rogue, the Alex-Mirale deck, etc. All of them lose consistently in legends even when people like Hyped are playing them.
Cult Master will work on all minions, not just Beasts. It is a move you can do on an active board as opposed to needing to combo everything on the same turn, and as a Hunter you want to be maintaining board control so having a board with minions on it is kind of a gimme. Think how much better Haunted Creeper will be when you draw two cards for its deathrattle spiders. It has better stats (4/2) for less mana (4). Buzzard was the primary reason Hunters actually used their Beast cards. Half the Hunters currently on ladder play the Deathrattle with traps and bow variant which already cut way down on Beast related cards. This'll just cause them to drop the rest.
I guess we'll see, but I'll say it right now: top tier decks in tournaments and high legends will not be using Buzzards. And if they do, they won't be winning. We can come back in a couple of months and see if I was right.