Crews do maintenance overnight.
Then when CM’s go in in the morning they have to do all the safety checks before the ride can open. If something is wrong then that’s when you’ll see a ride still down when the park opens. Sometimes the fix requires a little more time.
But if crews didn’t come in at night to work on stuff, then nothing would ever get done since the park is open every day.
I’m sure there’s no doubt Disney knows about the current rips in the painting and will indeed fix them, but my guess is their currently working on other stuff and that’s not at the top of their agenda.