I recently learned that of the reasons for this neocolonial population control is to make sure that over-exploited regions don't become problematic once their natural resources are fully extracted.

Over-exploited countries are essentially forced to be dependent on the US for food. They pay for that food with some of the money generated via resource extraction. They have no agriculture of their own beyond cash crops like cocoa or coffee, which obviously cannot feed people. So once those resources are gone, the money to import food is gone, and these countries will have to experience some pretty serious population reduction before local agriculture can sustain the remaining population.

It's not just individual malthusian billionaires peddling this either, this has been official World Bank and IMF policy since the seventies at least.