I heard about this rumor a while back. I'm a little bit on the fence with this.
The rumor, as I understand it, is Indiana Jones replacing DINOSAUR due to the rides similarity to another even older ride at another park, taking the uniqueness away from both (at least favorable if not actually great) attractions. Some other rumor involved a South America themed land with native fauna and cultures like Africa and Asia, but I'd dismiss this seeing the currect direction WDW seems to be taking in the parks. Plus you don't need Indy in S. America. But that isn't me saying S. America woudn't be cool. I'd love it, but if it ever did happen, it won't anytime soon.
Indiana Jones very well can fit Disney's Animal Kingdom, and I love the park so I do understand how the DL ride could interfere with DAK's true theme. However if they desire to use the IP, they could do as follows: build a brand new ride in Asia or maybe even Africa, and instead of igmorantly and needlesly shoehorning in a completely unrelated study in paleontology (the study of prehistoric life), celebrate the side of archeology (Indy's profession) that focuses on nature's effect on man, and man's effect on nature. Explore an ancient forest and cave, maybe incorporate a temple, and tell a story that depicts and explores the relationship between man and beast/nature.
If you try to mix Indiana Jones with dinosaurs... then.. no. Just don't do it. Lol. In no way does Indiana Jones fit with dinosaurs, he has no knowledge of dinosaurs and doesn't care about them any more than a normal person. It wouldn't even look right... you might as well put Zootopia in DAK. And nobody wants that lol.
Disney's Animal Kingdom is such a cohesive park, and for the most part everything there is well done - except Kali's boredome in lack of story and awe and Na'Vi's lack of wildlife in an animal themed park... not too mention its short time frame... but I digress. It's a great park and I think any new attractions should be weighed carefully. Whatever comes though, Rohde has my trust in that I think that he can handle it. Pandora wowed me - as someone who appreciates ecology, they made me believe that Pandora had a very specific ecosystem and they really did well with the whole concept.
Plus, prehistory is crucial to DAK's core theming and thus should NEVER be eliminated. Prehistory should always have one land at least, dinosaurs in particular.
So yeah, Indiana Jones can be fit into DAK. But to quote Ian Malcolm with a better question, should they? Sure you can, but Indiana Jones isn't needed at DAK and is at DHS. I mean I actually like the idea, and I think the park would do well with a park that that explored the history of mankind and nature in a cool, adventurous Indiana Jones style attraction. But I still wonder if Indy is not better served with a land in DHS. Since DHS can't have a Marvel land as of now.