The right arm becomes redundant as you go into final release before impact. That has been proven in scientific studies. It does it's work in the backswing and then in the downswing to just before impact, when it literally vanishes kinetically. Of course, you must continue thrusting with the right arm to ensure that the right shoulder continues to rotate or else your shoulders will block.
Here is Miura's diagram on swing loading:
Note the change from tangential to radial loading. The right hand and arm contribute to tangential loading while the left arm applies radial loading or "goes normal".
Now, having said that, I have used a dominant right arm swing for short chip shots where the right hand holds on to the club throughout the swing.... and the left arm is only a control radius.