I think there are pros and cons to washing. Like if I was making a quilt as a gift, I would not wash it. For years I have washed fabric first because most quilt books say so. I have trouble getting all the wrinkles out of the material with my iron having steam on. If the pieces are wrinkled when you cut them you will not get as good of a fit when you are making the block. So after pre-washing for several years with no shrinkage in this modern age, quit. I will take my chances.
Have had to wash a couple of quilts because I could not get the disappearing ink out even after dampening the quilt.
IdahoSandy