I agree with washing the batting if it is not a big wall hanging. Shrink the batting before you put the layers together. Did you wash your fabrics before making the quilt top. Yes would be a good answer to this if you are concerned with shrinking and want the quilt to be flat. I use Warm and Natural in all my WHs and they hang very nice and the quilting has enough dimension for character, not to flat or to lofty.
peace