If there were Kings in Africa
It would not mean that the primary ancestors of African Americans were Kings because there are usually more subjects than Kings
It is possible that the each King reproduced with more women than all their subjects combined so their primary ancestors were Kings but if this was the case there would most likely have been a lot of incest in their ancestry
If their slave ancestors were Kings they would have lost to other Kings before being sold as slaves to Sephardiim
There are plenty of "Coming to America" of African royalty.
They are poor.
The king rules over a hundred poor people and the prince goes to NYC and drives a cab and sends back money.
American blacks are the descendants of slaves because the US did a better job of not killing their slaves and breeding. There is almost zero African connection.
Plantations had generations.