I think the reason Disney is reducing hours is because they are worried (and they have more data than we do, so probably justified) that fewer people will be traveling when school starts, even than would have in a normal year. The low attendance now could be even lower when locals are in school or working during the week. With even lower crowds, keeping the parks open those extra hours will be kinda ridiculous.
The weekends will likely continue to be as busy as they are now, so I think they should keep weekend hours the same.
I foresee them returning hours to normal whenever attendance consistently reaches capacity, and more so from resort stays than APs.