I think Steel-types have nerfed almost across the board. Although it received both buffs and nerfs from the new type chart, the big issue is that the best Fairy-types in OU are just Togekiss and Azumarill, and their match-ups vs. Steel-types really haven't changed that much. I suppose Mega Mawile is a new threat that bulky steels can handle well (I'm not entirely sure of its movepool but I know I've been handing it with M Aggron), but that doesn't really match up to Gengar, Hydregion, Aegislash, and Tyranitar who can now spam those Dark and Ghost moves much easier. I dare say Hydregion, who used to forgo Dark STAB altogether, now has an easier time spamming Dark Pulse than Draco Meteor (though DM is still the money move).