The Astros are NOT the first to use this system. My son was drafted by the cardinals and this had been implemented by the then farm director, Jeff Luhnow.
The players hated it, the pitching coaches hated it.
I believe this system may have been a result of many of my sons and others pitchers issues who were in the system at the time.
The whole idea is based around developing as many starters as you can, not to cut down on throwing.