bonafide11
Worker
I go back and forth with the Zulu. Apparently they actually do have a "Civilization" of sorts that separates them from the barbarians in the game, but they're also synonymous with fighting and losing to the British. The Bantu migration is one of the more dramatic elements in history and the Zulu were the greatest empire to come out of that. In the end, I think they'll be useful to add.
They're also quite distinct from Songhai. Songhai was a Saharan Afroasiatic civ. The Zulu are true Bantu, subsaharan African. They're the only Civ I can see being added from subsaharan Africa, anyway (Moors are similar to Songhai ethnically, Carthage was Middle Eastern, Ethiopia is its own thing).
I'm not saying the Songhai are similar to the Zulu in history, but in the game, Zulu has always been a militaristic Civ, and now the Songhai are as well. If, besides Egypt, there are only two other African civs, I'd rather them not have a militaristic bias in the game. That's why I said it was nice in Civ IV: Mali's focus was gold, Zulu's was military, then Ethiopia was culture and expansion. They had three diverse African civilizations from different geographic regions. With the Songhai being in the same geographic region as Mali, they likely won't add Mali, which leaves Zulu or Ethiopia (or someone else). I doubt it will be Ethiopia, so it'd more likely the Zulu, who gameplay wise, would be similar to the Songhai.