Jeffrey,
I should watch it again before posting this comment, but I have crap to do this morning ...
I don't think that he implied as much, and he certainly didn't state it outright, but I don't think that, for this piece, this is his point. His point is to stop cuing the lat (which I only partly agree with).
He also seems to be discussing only overhead work ... things change in the pulls. However, think about the OH squat - this is all scap elevation. But also think about how it gets there: if you snatched it up, the scaps went from depressed (packed) in the pull, to elevated in the "catch".
If you're just working the OH squat, and say, BTN push-pressed, or jerked it up, the scap again goes from packed before the jerk to elevated after the jerk.
The press is different ... some people go from depressed scaps at the start to elevated scaps at the finish, though if you watch closely, this occurs nearer to the finish. Other keep their scaps depressed the whole time. Why? There are a range of anatomical differences among us.
The scaps float on the ribcage, so as long as they are stabilized AND positioned properly for the given movement, what's the difference which muscle groups do this? I like the idea of antagonistic muscles firing hard in order to get the agonist muscles to fire harder ... in the case of the press, the lat antagonizes the shoulder flexors.
Building a tight platform with the lat and other scap stabilizers to press off of, I feel my lat reduce force production as my shoulder begins to flex, allowing it to flex more forcefully (I guess). Toward the end of the press, the trap shrugs my shoulder hard to lockout. When I fight this natural tendency to shrug, I can't lockout as much weight and it's not as forceful. This is "active shoulder" ... but, this is me, not everyone.
Well, I should have just re-watched the video then ...