I usually plan a late August/early September trip. This happened in 2015, 2016, 2017. It is extremely frustrating. Yes, you can make guesses based on the past, but my experience each of those years was that I ending up shifting stuff around once the hours did come out. It was an annoyance to have everything settled and then feel the need to re-scheduled it.
I don’t know when your trip is planned, but keep in mind that the last 3 years at least, the hours in September were not exactly the same as August hours. For example, Fantasmic time changes from 9:00pm to 8:30pm after Labor Day. Halloween parties cause early closing in Magic Kindgom — this caused me the most difficulty last year.