I think the better answer is neither.
Putting a cartoon dark ride, any cartoon dark ride into the African section of Animal Kingdom would completely destroy the thematic integrity of the land. With few exceptions (Nemo musical, Tough to be a Bug, meet and greets) all of the attractions at the various Animal Kingdom lands maintain the themed reality of their host lands. Everything is occurring where and and when it's supposed to be, making the immersion higher than any other theme park Disney's ever built. Train rides are train rides, raft journeys are raft journeys, and safaris are safaris.
A Lion King ride on the other hand, even a very nice one, would likely do what most of the Fantasyland dark rides do- have some sort of barely-themed omnimover slowly drag the rider in and out of several disparate scenes that tell a disjointed and abbreviated version of the film it's based on. There's nothing wrong with this approach in Fantasyland, but nothing else at Animal Kingdom uses this approach.
I'm worried enough that "Festival of the Lion King" going into Harambe is going to hurt it, but at least they can play up the actual "village festival" angle on it, which would be culturally insulting, possibly, but may be the best route here.
