It's interesting that he mentioned both of these bending features because some of the guys doing advanced shaft fitting take into account the bending characteristics at different points (zones) in the shaft. Specifically, the swing tempo may be considered for "Acceleration Bend" (using your terminology) and release quality for "Release Bend".
As I mentioned earlier the "Release Bend" is generally toward the target for almost all golfers (for full swings) and is caused by the centrifugal force due to the clubhead speed pulling outward on the shaft through it's center of gravity - thus, CoG wants to line up with the shaft axis bending the shaft forward. That's why offset heads tend to hit the ball higher and could slightly correct a fade because the CofG is further behind the shaft and the shaft will tend to bend more forward with these heads. Ok - maybe too much information there.
Still a little dubious on the impact deceleration concept - but it may be a "real vs feel" thing in that it helps to think about accelerating through impact to avoid quitting, throwaway, etc.
/////////////////////////////////////////////
Some pictures showing these bends would be nice... or are they too subtle to see?
PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
ERROR: The request could not be satisfied
504 Gateway Timeout ERROR
The request could not be satisfied.
We can't connect to the server for this app or website at this time. There might be too much traffic or a configuration error. Try again later, or contact the app or website owner.
If you provide content to customers through CloudFront, you can find steps to troubleshoot and help prevent this error by reviewing the CloudFront documentation.
Generated by cloudfront (CloudFront) HTTP3 Server
Request ID: Frtvlb6WorYNO019S8T7jgbOlDJkLm-QLH0aJgv2fqMUEYq1Tzw14Q==