Both things are totally different.
If you think that pronation is a source of energy, you try to use muscles to reach the nonexisting goal. As a result, you can force your wrist (because you will experimentally discover that this action generates more energy when the racquet is not in line with your forearm).
If you know that pronation is NOT a source of energy, you just use your forearm to rotate racquet's head. You do that just before contact with the ball, when your arm is straight, so your wrist is safe.