Do you have enough extra that you could try it on a test piece? I looked it up and it says the fibers are heat bonded, so not sure that prewashing will help; however, worth a try.
I think that most polyester battings can be soaked, hand-agitated, spun out in the washing machine and machine dried without falling apart. (Never allow machine agitation, of course!) Many cotton battings can stand this also, probably because they are needle-punched.
Traditional cotton battings such as Mountain Mist Blue Ribbon cannot be soaked and dried as they have no bonding or needlepunching at all; they will fall apart.