Since the events of Midnight will be happening in Quel'Thalas I think there is no reason for Blizzard to not touch the troll theme. They've been living there forever and afaik has not gone anywhere. Lore wise I assume the most amani thing they could do is to wait for some bad events to happen and strike the elves once again, but since rainbow and friendship is a thing rn in WoW the most reasonable thing to do would be to talk them into joining The Horde. Good reference of how they should look like would be Zul'jin from HotS. Honestly there is no reason for Zul'Aman 2.0 to not happen.