I think down the road I wouldn't be shocked if they added small-medium sized animal enclosures.
I would be shocked if they added any animal enclosures after the initial buildout. The last time any new enclosures were built at the park was during the 1999 Asia expansion, 1 year after the part originally opened. In the 25 years since then, nothing. Sure they've rearranged some of the animals within those exhibits, but they've done nothing for the park's overall capacity nor the number of things for a guest to experience on a given day.
On the one hand, this is expected. Animals are expensive, and much of the park's early budget issues were blamed on the care facilities costing more than expected. Animals are unpredictable, making it tough to guarantee all guests will have positive viewing experiences. Animals are difficult for viewing by large crowds, making most traditional exhibits very low-capacity by theme park standards. And animals have a lot of needs, including ongoing care requirements and limited hours that guests can/want to observe them. If you're an executive planning the park's future, of course you're going to prioritize things that are cheaper to operate with higher capacity and reliability.
But because of all this, if they are ever going to actually add more animal experiences throughout the park, they're not going to do it in a peacemeal fashion: it's going to be done as part of a major addition/reconfiguration, like a new land. Regular exhibits cost too much and don't have the capacity to 'justify' their addition as a stand-alone item; they would have to either be wrapped into a larger project, or be incorporated into some sort high-throughput attraction like the Safari.
The park was always master-planned to have the animals mostly on the north side near the main care facilities, and park operations facilities focused mainly on the south side, which makes this location challenging. However, they're redoing a large enough area and have enough backstage connections to the animal support facilities that it wouldn't be overly difficult to find a way to make it work; it wouldn't be any more difficult than caring for the animals in The Oasis. There are countless ways that live animals could be incorporated into this new area, they just don't want to do it.
Avatar was able to get away with not having animals because the animals in the film don't actually exist and we were promised the land's upsides (weather-tolerant indoor attractions and atmosphere requiring longer park hours) would offset that drawback. At the time there was plenty of skepticism about a land at DAK without animals, but that was outweighed by the lively energy and long hours the first couple years it was open. Now that the novelty has started wearing off and the park's rarely open after dark, it's tough to walk through that area and not feel like something is missing that makes it feel different from the rest of the park.
Now it seems they're not even trying to justify not adding animals: they're spending a boatload of money to redress an existing attraction, swap one spinner for another, swap one play area for another, and only add one new (D-ticket?) attraction. They're theming it all to an area known for its biodiversity, but they can't even manage to have attractions that focus on animal-related stories and instead are using human-focused ones that only have the most fleeting references to animals.
If they're not going to focus on the animals any more, then why can't they build more non-animal things to do? Why can't they manage to fix the goofy operational hours that revolve around when animals are active? Why does this park simultaneously not have enough animal stuff to be a real zoo-like experience, not have enough non-animal stuff to be a regular theme park, and just generally not have enough stuff for the average guest to fill a day without waiting in brutally long lines?
If they're going to try and fix the problems of this park (and, to be fair, all 4 WDW parks), then they need to build a lot more of everything. Every little bit of capacity helps, but instead of adding things to make the park stronger overall, Disney only seems interested in redressing what's there, which will inevitably increase demand without the corresponding capacity increase to offset it.
I'm way late to this party, so somebody may have already pointed this out, but Disneyland sees almost twice as many daily visitors as DAK on average. I would assume that plays into wait times. If you're going to use wait times as a metric for comparing popularity, you need to account for all variables.
Disneyland also has well more than double the attraction hourly capacity of DAK and also regularly operates much longer hours. Considering just E-ticket type attractions (acknowledging that there's a wide range of capacity within that category), DL has 13 (Jungle Cruise, Indiana Jones, Pirates, Mansion, [soon to be Tiana's], Rise of the Resistance, Big Thunder, Mickey & Minnie's Runaway Railway, it's a small world, Matterhorn, Submarine Voyage, Space Mountain & Star Tours), while DAK has 4 (Flight of Passage, Safari, Everest, Dinosaur).
On a typical summer day when DAK might have 12 hours of operations (8am-8pm), DL will regularly have 16 (8am-midnight). DL also doesn't close half of its attractions several hours before the park closes because it's starting to get dark. While DL's operations and entertainment still haven't fully rebounded after Covid, the park's bones are much better suited for the crowds it gets than any of WDW's parks.
