Disney parks are not cheap and the prices continue to go up but at the same time, if you are not paying attention, you may find your day shortened by an extended hours event or a ticketed after-hours party. In the case of Animal Kingdom, you need to expect a shortened day.
Animal Kingdom is the one park that closes early every day. There is no nighttime show of fireworks or anything else. Disney says that it is because of the animals, and it makes sense. What doesn't make sense is the early closing. There is no reason for AK to close earlier than other parks, and using the animals as an excuse is nothing more than an excuse.
Kilimanjaro Safari's should close early. There are no lights out on the "Savannah" and there is no reason for the Maharaja Jungle Trek to stay open beyond six or seven in the evening. At EPCOT, The Living Land attraction, Living with the Land, will sometimes close as early as 6:00 pm and it doesn't change the traffic flow at the park.
Animal Kingdom is different and as a result, the park typically doesn't remain open past 8:00 pm. This week, the park will close at 7:00 PM on Monday and Tuesday but will close at 6:00 PM the rest of the week through Friday. Why? There are no after-hour parties or private events.
Disney invested much money in Pandora, the Avatar world created around the James Cameron picture. They even designed the area with bioluminescence lighting that brings it to life after dark. The problem is no one is seeing it, and guests who want to see the area lit after the sun goes down are completely out of luck.
It is unclear why Disney changed the hours at this park, but they need to close areas of the park for the safety of the animals. I suppose the problem with that thinking is that there simply isn't all that much to do, and maybe that is why they close early.
Pandora would be amazing at night. Actually, it is. I have seen it before they cut the hours of operation. That area would be a lot busier if other areas of the park were closed. Aside from Dinosaur: The Ride, there isn't much else to do throughout the park. You could ride Everest a few times, I'm sure.
Perhaps when Animal Kingdom gets a facelift in the next few years and Dinosaur turns into Indiana Jones and that weird little Dinoland area becomes home to ENCANTO, the park will extend their hours but for now, the real crime isn't closing early, it's charging guests the same amount for fewer time inside the park.