I think since the touching in this case has always been ignored, in the past there technically was no touching that could have put a new force on the ball. I agree this rule just clarifies it.
This rule DOESN'T clarify the case where you can legally bat a ball into an opponent though. The touching is ignored in that case, but the FORCE is not.
Play: 4th and 10 at 50. K1 punts ball to R1 at his 5 yard line. R1 muffs the punt, ball lands on 3 and is rolling towards endzone. K2 bats the grounded kick towards his own goal line, hits R1 at the 5. Ball rebounds off R1 into the endzone. Whistle blown as ball enters endzone, as this is a kick entering an endzone, play over.
The ball's status is still a kick when the bat occurs, so a bat of a grounded kick is legal, there is no first-touching as R touched the ball before the bat. The force which caused the ball to go into the endzone is R, so is this a safety?
(I don't see anything where a grounded kick can only be batted if untouched by R)