I think people have become a bit nitpicky on this topic. I'm sure there were pitchforks when the Navi were coming, but it turned out to be an excellent addition to the parks.
Zootopia is 100% about animals. It's in the name, "Zoo". Lion King is all about animals too. Both Lion King and Zootopia deal with human issues (love, death, family, comedy, hierachy) at it's core. If you stop there, you can make a movie all about animals fit into Animal Kingdom if it's done right.
That being said, Disney had a responsbility to make Zootopia work in the spirit of the park. From the early reviews, it doesn't sound well executed.