Its slightly annoying how three Subsaharan civs in a row are all merchant, but tbh there is not much choice
For ancient (pre 1000BC) there really is no option other than Nubia (by current knowledge of course - SA would have so damn much potential of archeological research if they had money, stability, infrastructure and global interest). And Nubia really doesn't deserve other focus imo (builder, agrarian and aestethe are all, well, nice but still league under Egypt). No expansionist either (actually Egypt under New Kingdom would deserve this focus), and no scientist (tbh wouldn't even give this to Egypt after reading about their miserable "mathematics"). And militarist seems off.
For classical your only well documented options are continued incarnations of Nubia and Axum (civilization in Nigeria reaches this era but it is still barely known to archeology, as I said). Both are best summed up as merchant civs.
Civilization in Somalia reaches ancient era (Punt) but terribly documented until medieval and of course 150% merchant focus
Finally there is an explosion of civs in medieval era. Ghana, Mali, Kanem, Hausa, again more Nubia (Makuria, Alodia), Ethiopia really emerging and much better documented than Axum, medieval Somalia, Swahilli, Zimbabwe..
And all those civs apart from Ethiopia are best summed up with merchant focus!!! The only real alternatives is making Mali into expansionist (you should agree this already feels off even if it makes sense), Ethiopia or maybe reaching for Nigerian civilizations (unfortunately it seems no other human is fan of Yoruba civ besides me).
I really hope we won't get more merchant SA civs in 1.0 release

Regarding next era there are possibilities for expansionist (Songhai), militarist (Ashanti, Benin, Yoruba kingdom of Oyo), aestethe (Kongo, Ethiopia imho), idk (Merina in Madagascar)...
In industral era I vaguely recall some bleak hints we again get Zulu (sigh, if you want militarist anti colonial civs then Ashanti are so much more impressive, or damn Ethiopia which actually managed to win this period).
And I'd be damn surprised if we didn't get Ethiopia in modern era then. By far the most important 20th century African civ, with only possible contenders being Nigeria (less known in West), Kenya and Ghana (disqualified by medieval Ghana

).
And South Africa but I think nobody would like apartheid state as modern reprezentantion of Black Africa lol.
I have changed my mind, in the future I am not against Mali getting scientist focus. It is far fetched a bit but if any Subsaharan civs should get sci focus then it should be Mali, it actually had proper "hard" scientific knowledge for few centuries, in Timbuktu and Sankore. I just hoped this isn't THE ultimate scientist civ for 1.0 medieval era release lol.