Not necessarily. You can shoot arrows that are way overspined and often get good groups. The problem comes when you try to get fixed broadheads to shoot with your field points. Real tough to get it tuned.

With expandables, you might not even notice. What is happening, every time you launch an arrow, is that the stiff arrow is wanting to angle to the left and the fletching is usually able to mostly straighten it out. Not the best scenario for energy efficiency or arrow penetration, but it will work. If you were to shoot an unfletched shaft, you would see it flying through the air into the target at angle left.