It seems that a lot of the comments on this thread didn't really read the article or understand what the intent of the study was.
The study was a PoC study to prove if a mechanism exists to explain stretch mediated hypertrophy, *independent of other hypertrophy stimulus*.
It's not a suggestion that orthotic stretching, or even passive stretching in general, is an optimal way to get buff.
It does provide evidentiary confidence that stretch mediated hypertrophy is a real thing, independent of other variables, such as ROM.