That's a bat being thrown/whipped by the hands.
You still haven't said anything about the 3rd dimension.
Griffey's bat is moving very fast in a dimension other than x and y.
That doesn't happen if it is being held back.
That only happens if the hands are active...
.and I believe they are throwing the barrel around the resisting lead arm/hand at launch..
That is why over each frame of his 4 frame swing you can see his barrel moving very fast..
AND....that is how your bat/forearm angle can remain the same while the hands create speed in the 3rd dimension..
That speed can only be created by the hands at that point in the swing.
I guess you were real proud of that post.....several things repeated over and over and over...
Nowhere did you really discuss the z axis.
The shoulder/torso turn is in the x and y axis....that will not develop speed in the z axis.
The point is.....there is speed BEFORE the bat and lead forearm line up. BEFORE what you called 'flyout'. Your 'hold the back bat' until release deals with the bat lining up with the forearm. It deals with 'flyout'. That is what your pendulum link showed. And that is fine.
But, there is clearly something else going on..
Only the hands somehow throwing or pivoting the barrel around a pivot point....the lead hand....will this z axis speed be seen...
The hands are most definitely capable of developing some throw or whip type speed. Are you saying pitchers just let their arm dangle and the rotation causes it to eventually 'flyout'. I think not. Their arm action is very important to them.