This stretch helped me in many ways. One problem I was facing with the alignment of my body was the position of my shoulders. To have a good line, you should be able to lift both arms and have them parallel with your neck.
My shoulders were a bit twisted facing forward. Making a lot of shoulders rotation exercises incresed my stability, but as a side effect made my shoulders muscules very stiff.
This particular stretch affects small muscules and connections around the capsule that attaches your arm to your shoulder. If you are working to open your shoulders and improove your handstand line, give it a try.