I have washed Warm & Natural in my front loading washer on the handwash cycle and then dried it in my dryer. I know it shrinks unless you do that before quilting. I've not had any problem with the batting coming apart or seen any downside to pre washing it. I did a quilt last year for a newborn without prewashing. Because of my dogs I told the mother she ought to wash the quilt before she used it with the baby. I've never seen her use the quilt and I'm sure it's because it puckered up a whole lot after she washed it.
Linda