[Alternate history] What if Sub-Saharans had no immunity to smallpox?

[Tomenable]

What if Sub-Saharan Africans in 1500-1600 AD still had no immunity to smalpox and other European diseases (as was the case in reality with Native Americans)? How would have Africa looked like in 1900-2000 AD in such case? Would it be like Latin America, with some parts being majority White, other parts racially mixed, and only some parts having native (in this case Sub-Saharan Black) majorities ??? For example, I guess that South Africa would be like Argentina and Uruguay - with 90% or more of people being Whites. And what about Blacks in the Americas? Had Africans been decimated by smallpox, there would have remained not enough people there to enslave and export across the ocean. So I guess African-American Diaspora would never come into existence in this scenario ??? But how many European or other (Asian?) settlers could such places like Central Africa attract, even when depopulated by smallpox?