I think they're just trying to keep up with their direct competetor, DAK. The timing of the announcemen makes it pretty clear that it is in direct response to Avatar. Falcon's Fury was announced before Avatar was officially revealed, and since the park was already doing a major revamp of the Timbuktu area of the park to accomodate the new ride, it makes sense to rebrand the area to directly go against Disney. I'm not crazy about the name (names coming out of Sea World Entertainment lately have been pretty terrible), but going away from the exclusively African theme is not such a terrible thing.
Perhaps they will eventually get around to retheming the older part of the park to reflect different parts of the world (you could say they've been slowly doing that over the past 10 years), but in order to do things right, it's go to be one step at a time. Timbuktu was one of the oldest parts of the park, and still features some of the oldest rides.
Walt Disney World