Louis XXIV
Le Roi Soleil
If you're going with the logic of patch = hint of what DLC is coming, then I vote Vikings. There's plenty of naval/embarked unit fixes in there, and well.. the zulu aren't known for their navy.
Interesting. As a third option, I'm going to throw out the possibility of a Punic War scenario. If they were to add Carthage and the Celts, there would be a need to fit in naval war along the path from Italy to Tunisia along Sicily. If they were to incorporate the Dunn (UB in past games) as a unique improvement, it would make sense to want to treat it like a Citadel (hence the AI improvements there).
That being said, the Vikings/Norse/Scandinavians make a lot of sense. Citadels would be logical for any Medieval-esque scenario. So I could see either way.