I think those you hear that run them on a timer so it because they do not like the sound of it.
Some run them at night because plants do consume oxygen when the lights are out. So I think the thought is it helps regenerate some of that. But they also produce oxygen during the day while they uptake c2o in the water. Not sure how much they truly consume but, I have read that many times.
So in short oxygen is a good thing for the fish regardless and the plants will use some as well. But I wouldn’t worry that it will make or break your planted take though either.