My suspicion is that if this is what they are doing instead of a new race/s, they will do one for everyone, just these ones are the only ones that are, A, already in game (Highmountain Tauren, Lightforged Draenei and Nightbourne) , or B, ready (The Void elves).
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The Highmountain Tribe has different war paint markings. People have been asking for Wildhammer Dwarves for a while, and literally the only difference there is the tattoos.