We’re going, be happy there’s such low crowds that time of year, as most local kids are back to school. The teenagers can enjoy evening pool time, or go into CityWalk, as opened until at least midnight that time of year.
While not dark at night time park time, you can get a lot done during the time the parks are open, and build in pool time and other. I, personally like to relax on my vacations. So early park closing times don’t bother me at all. I’m sorry you feel disappointed. Just means, go in Winter time, when standard time has sunset at an earlier time, if you want darkness while park is open.
When we were there in middle of January, earlier park closings week days. Didn’t bother us. We relaxed by the pool, saw a movie, played mini golf, and drove to Downtown Disney for a meal and shopping there one night. We went into Volcano Bay the last three hours they were open one week day, and was fun with so little crowds to be able to have little to no line, even for the coaster, was awesome.
For one, the only time I have ever seen both Disney and Universal change to more hours, was when the crowds were larger than expected. I for one, would much rather have a few hours less time for park fun, in exchange for much lower crowds and very short lines for rides, shows and food.
As a famous song said, be happy, don’t worry.
Best you can gauge crowds is to watch the pricing of an express pass. If it starts to get more expensive, you can assume they are thinking more crowded.