That is one of the ways that I sometimes finish a quilt. I know a lady who always puts right sides together and sews all around the quilt, leaving a small section to pull the quilt through when she has finished. She then finishes it off with an invisible seam in that section and does some straight stitching to adhere the backing to the quilt. All of her main quilting is done on the top and the batting, so you can't see if there were stray threads at the back when she quilted it after it is encased in the backing fabric. Her quilts look perfectly fine.