It's not what JD claims though...
Yeah. I think that statement was a refutation to the ‘don’t open your front side/foot’ crowd though.. JD also says he never wants to think about his hands BUT he says in many other videos that he wants to ‘punch’ the ball w his top hand. Same goes for ‘get on top’.. he then claims that you gotta keep the barrel ‘up’ in later videos.
These cues are a sequential refutation imo. Not an absolute that he never uses those body parts/cues to stay closed, on top or to strike the baseball.