If that theory is even true, that still doesn't make anyone African-American. Your heritage might be, but the only people that truly are African-American, would be someone who was born in Africa and moved to America.
If mankind originated in Africa, how are we not all African-Americans?
(In the 2000 census for the first time the Clinton administration allowed identification as belonging multiple racial/ethnic groups. The family lore (since confirmed by 23andMe) was that I have some Latino and some Indian blood. I checked off most -- or almost all -- of the boxes on the 2000 census form. For 2010 my wife grabbed the form, filled it out and mailed it back before I even discovered that we had received it. I think she was afraid that an Obama Department of Political Correctness SWAT team would arrest us and send us off to Political Reeducation Camp. I can now prove, it, and if I had the chutzpah of Elizabeth Warren when I applied to colleges, I could be a full professor at Harvard today! Admittedly, I look more like Custer than Sitting Bull but I'm becoming more and more convinced that "race" is an outmoded 18th century concept.)