We've been here before (and not just with my flying....). Pretty sure that a comprehensive survey of the HUMS data proved that no limits were being exceeded during the display a few years back. Perhaps the Mk4 has some additional sensors and Boeing are concerned about the impact on the TLCS maintenance profit margin. Shame really - it's probably done Boeing's sales book no harm over the past decade.
The Puma display? At least it was more dynamic than the Merlin one, without the need for a Banana Splits vehicle to try and liven it up.....though, of course, throwing lumps of earth off your undercarriage having gone ploughing with the nose gear is always a crowd pleaser.
OOT - the US Army don't fly the aircraft anything like as hard as we do....hence why some "interesting" corner cases in the flight envelope on later Control Laws were only found by UK pilots once we started flying them. I took a 4000hr US Army pilot flying once for a routine LL training trip on an exercise. He was staggered how we flew the aircraft in terms of height/speed/AoB - all way in excess of US Army norms. Not saying it's right or wrong, we just fly it differently.