I don’t consider any deck to be a true boogeyman at this point. The only reason Ironworks could have been in my mind was the incorporation of Explosives and the rules exploits. Every deck that I know about can be beaten by any deck if they want to do it and by normal means, so I don’t see anything taking Ironwork’s place for the time being.

As for Looting, that’s hard to say. On the one hand Looting is the best graveyard enabler in Modern, the best velocity card, and arguably card advantage. However, no Looting deck other than Dredge has stuck around very long. Last spring everyone was singing Mardu Pyromancer’s praises and today the deck is non-existent. Similar story for Hollow One. There’s no reason to think that Phoenix will be any different, and so no reason to believe that Looting needs to go.
That said, on paper Hollow Phoenix is a very scary deck though it’s done nothing in reality. If someone finds a way to really unlock its power then Looting would be the card to go. Unless that happens or another incredibly broken deck emerges, I think Lootings safe.

There was some silly talk on Twitter before and after the B&R that “Mox Opal is the Workshop of Modern”–implying that its status as one of the most expensive cards in the format renders it immune to scrutiny. The comparison to Workshop is doubly silly because KCI is the first card *ever* to be banned from an Opal deck since the Mirrodin artifact lands were put on the initial ban list (Eggs didn’t play Opal because simultaneously recurring multiple copies of Opal didn’t work under the legendary rule of the time–all the copies would die before you could use any of them). The Vintage restricted list, on the other hand, is littered with artifacts that have only ever seen play in Workshop decks.