That sure does not look bad to me! We get some pretty wrinked quilts to work on at church where we take in quilting for others. What you have shown can be quilted out! :lol:
I was taught to prewash when I stated quilting. But I seldom prewash now. When I prewash the fabrics for the top, I try to remember to prewash the fabric for the back as well! But I never prewash the batting, so everything will shrink or distort at a different rate, so it will look like the old fashioned quilts after a wash or two anyway!
My older fabrics in my stash are prewashed, but the newer ones are not. I tend to mix them and enjoy! A girls got to take a chance now and then. :?