Defoliation is a very good idea! For example if the plants do not have well enough wind cycle blowing the leaves around the plants leaves will than start to sit on one another and create little damp pockets creating a cavity looking for trouble. Plants perspire from all around the leaves and if bunched up under one another with no light, wind, and freedom it could create some unwanted trouble.
I always deforliate my plants once they lower inner new growth cant see the light I also give my plants spray down 1-2 times a day and they love it, I try to create my own little rain forest type jungle for my babies.