In BFA, Rexxar uses a highly unique half-ogre model with attachable armor pieces. It uses the Kul Tiran rigging with a slightly adjusted body (no belly) and has a very distinct face model you don't even see normally. It's not the special NPC type of model used for important characters where the clothes are built into the model.
Kul Tirans being the only characters with completely new body rigging being developed suddenly makes a lot more sense if its theorized that that rigging will be used for ANOTHER half-giant race on Hordeside to justify the resources and development put into it. It also lines up with Blizzard choosing to use Draenor instead of Outlands for the Mag'har, as this leaves Outlands open to grab the Mok'nathal from.
The question is... if this is actually an upcoming allied race, how the hell are they going to be involved with the story?