I think there is a risk for african white people to loose their population in Africa. In the past, there wasn't any touch between black and white people but now the people are more free and open minded. African people will be the first nation in the history which defeats the other nation by their manhood...
There was always interracial sex in Africa. The European Dark Ages were triggered by the demand for white slaves to be taken to North Africa depopulating southern Europe. When white traders visited Africa they were offered black women. When whites started settling there it was common for white women to be bedded by Africans. the 'Happy Valley' set in Africa were not racially biased in the way the Boers made interracial sex taboo in Southern Africa.