At university, I studied zoonosis (travel of disease from animals to humans) and the introduction of AIDs to the world from Congo. The most likely theory (to me) is that when cities were developed to physically concentrate and economically exploit African people and resources, along with the associated international travel, it was an unhappy accident that contributed to the success of diseases that would otherwise transfer from animal to human and then die out due to the physical separation of populations.
You don’t think Africans would have any incentive to urbanize like the rest of humanity? This didn’t even start in a city. It’s a remote rural place which is why there’re so many malnourished people.
The OP explains (correctly) that this diseases could have started several times in remote areas just to self-fix later, because remote rural areas aren't connected with other people and because bat viruses were first plant viruses. They are very fragile out of any cell. The presence of cities helps greatly the viruses to spread and survive in human hosts.
That still leaves the descriptive claim about urbanization exploiting Africans as if they'd be better off in their impoverished warfaring rural tribal communities.
