Somerset Val, the wrapper that you have is up-to-date. You can decide if you want to prewash it. If you don't prewash, it will shrink later when the quilt is washed. If you do prewash, it will have little to no shrinkage when the quilt is washed later. You choose. Either way...W&N batting will work.
I did not prewash and used it in a baby quilt. It did shrink after the first wash which gave it the antique look.