The last 2 pool closures (CBR and POFQ) both opened on time. They don’t give any clue other than will be closed “through June”…kinda vague. Depending on when you go in Aug, you’d have at least a month’s buffer.
Disney is famous for not telling anyone what is happening. But if you look at what happened when other resort pools went under an extended maintenance, they didn't change the layout of the pool. There are a few exceptions, like the main pool at Wilderness Lodge added wider stairs into the pool. But most of the refurbishments have been routine.