disclaimer, this is NOT ment to be a racist post at all. This is ment for speculation and lore discussion.
With the introduction of Black and asian humans, it leaves us to wonder where they hail from. With other races, various skin colors and breeds we have homes for them. Dark iron dwarves from blackrock. Green furry trolls from the forsts.. etc.
Now with human kingdoms, almost all of them are based of European countries, mainly English. with a few variant European nations.
With the black humans, we could always say they are from more hot areas. We have desert thiefs in tanaris and uldum? maybe there could be towns and villages? Or just nomadic.
But asians, I dont see where they could come from, as humans didn't live in pandaria pre-mists. So where might they be from? Or maybe if we had a new nation of humans that were hidden away? After all, gilneus walled off for years, and kultiras was off doing their own thing since WC with very few being seen pre- BFA.
Edit: The point of this thread is to speculate, head cannon and come up with fun ideas of where the variant humans are from. From a made up land that currently doesnt exist, or a way to fit them into currently places, like someone mentioned an island off of pandaria that was never discovered untill now. And someone else mentioned other side of azeroth.