Disney's Animal Kingdom is the most thematically consistent park Disney has. The fact that you question this means you do not fully grasp the themes which are DAK. DAK is not just a park 'with animals.'
Disney's Animal Kingdom is built around the intrinsic power and value of nature. It is both beautiful and lethal. Nature is at the parks core. Nature is wild; we bask in its glory and are humbled by its greatness. Animals of all kinds live by core principles and by the laws of nature. Animals are nature and are its "rulers" therefore it is the animals which make the kingdom. This is the central theme which is first and foremost to the park.
It first displays that nature is beautiful, and then that leads us to why we must conserve it. It ties together a reciprocal relationship between man and beast (nature). The majesty of nature is the motivation for conversational message, but the majesty of nature (thereby animals) is #1.
Disney's Animal Kingdom is story driven and focuses on transformation through adventure. It is what ties the other two themes together, that we embark upon a journey and it will change us. Hence why the park must all be in 1st person and cannot have book report dark rides.
Zootopia doesn't just defy these themes, it is the antithesis of them, and therefore fits less in DAK than nearly any other IP. In Zootopia, the natural world is no longer existant and has formed into human society. There is no more nature, it is gone, and animals are gone as they have all now pledged to new rules; not to those of the animal kingdom, but to those of society. The basal principles which are nature are not not acceptable in this world. All of nature is undermined in favor of society. There is no wild adventure to be had, no conservation to learn through it, and first and foremost, there is no nature to celebrate, it's gone. The Lion King and other Disney films have animals talking but they are still animals, who must abide by animal rules and act as animals, face the same pressures which animals do. The Lion King - The Circle of Life. The talking or clothes bit isn't the problem.