I read it too, and it’s obviously got an agenda behind it.
The older style banana curve is not always the best option for some of the more modern bred warmbloods. The flatter cantle CAN be a better option for weight distribution so long as the end of the weight bearing surface does not extend past the last supporting rib.
The black saddle’s diagram is conveniently not on a horse, so I don’t buy the “location” of the COG on the diagram is an apples to apples comparison.
You’d have to put the same rider in the black saddle for a legitimate comparison.
The photo of the dad and kid doesn’t work as a comparison because dad is a biped not a quadruped like a horse.
The black saddle has a more forward flap so sure, adding the same larger block to the brown saddle would shove the leg and rider back, but the saddles are built differently. Put a more forward flap on the brown saddle and then make the comparison.
Not to say that a saddle with a very minimal block is not a perfectly reasonable option for many horses/riders, but it is not a one size fits all scenario.