Honestly in certain metas I could definitely see keeping Fanatics in the MD. He is really good against Survival decks, Mirror, Elves, Ichorid, and a whole bunch of randomness. He's just not amazing against some of the DTB's out there. Since almost every Zoo list has no 2 toughness creatures the rules change to combat damage does not really affect Fanatic. Many of the 2 toughness creatures out there are hatebears or Lords. You shouldn't have too much trouble against those decks with or without Fanatic.
I'd still play Fanatic if I wasn't so high off of War Marshall + Goblin Chieftain.

