I think that the advice about keeping the right wrist cupped throughout the swing is a bit overdone. In my humble opinion, it is excellent advice to maintain it through impact. What happens after that is neither here nor there, the ball is gone! It may be good to feel as if the position is maintained until after impact because that ensures that it is actually done through impact. Very good teaching pros advocate that the left wrist should be flat though the backswing and on the downswing until after impact but that after that the right wrist shoud straighten and that the left wrist should point to the ground at the end of the follow through.