Question on May park hours

I have park hoppers booked for May 18, 19, 21, 22, and 23. The Disneyland app suddenly lists park hours from 9AM to 9PM for these days… is that correct? Would there be any reason for the parks to close this early? I can’t find any hard-ticket events listed for these dates.

I think it’s unofficial more than 60 days out. I can’t even see those days yet.

Yes, I can’t see these days in the calendar yet either. But when I look at the ‘My Day’ page in the Disneyland app (see screen capture in my original post) for these dates it shows a Disneyland logo at the top of the page with ‘Park hours: 9:00 - 21:00’ underneath it.
Not sure if it’s a bug in the app or if the park really closes this early on all of these dates… I’m worried that I’ll miss out on the nighttime shows on most days of my trip.

I know there are Grad Nites on a few of those days, but I hadn’t expected these to result in Disneyland closing early.