In my opinion, there’s a reasonably high chance hours will be extended, particularly at MK (less so at the other parks). What Disney posts that far out now is sort of the ‘bare bones’ schedule to some extent.
They can change hours at any time, but generally speaking they’ve been doing a more or less material hours update for the month in question around the second week of the month prior. For example, they just did a bigger March hours update this past Friday. So for August, that’d be early July. But patterns/trends in updating hours can change, so just keep an eye out.