Ok, Now I have done lots of quilts with the paper left in...from newspaper to tissue paper. It does not act like a bit of Kleenex left in the pocket. It does not wad up. It just sort of melts into the batting and IS NOT AT ALL NOTICEABLE.
Good gracious if you are at all concerned then just make a sample up and wash it. No need to buy an expensive product when old phone books are still available. Take it from someone who's first quilt was a crazy quilt pieced on newspaper, washed in wringer washer and still won a ribbon at the county fair.