So far, we already have several TLs themed on regions that IOTL didn't host advanced native civilizations, host one. There is Jared's Lands of Red and Gold, Mississipi Rice, American Stinky Pigs, and some other TLs of a kind that I either may haven't known about or just currently am not bother to list here. All those TLs are about advanced organized societies in regions that didn't have IOTL.
So far, the only regions I know that, in this context, have been exploited are Mississipi Valey and Southeastern Australia, the former for several times and the later for once so far. However, I wonder if the planet earth still have some more areas that was able to become cradles of civilizations just like Middle East, Central Mexico and China IOTL. I'm not sure Mississipi Valley and Southeastern Australia are all we got here....