Agree and disagree.
They think (be leery of anyone stating facts here) that the rash of high level (professional player) TJ surgeries are a result of too much pitching at the youth levels. There is nothing that says "at pitch 101 his arm will go slinging off and that will be that" at the MLB level (or even the youth level to be honest).
As the parent of a pretty good youth pitcher this is a topic near and dear to my heart and the one thing I don't ever see spoken about enough is using pitch counts a s a guide but keeping an eye on mechanics. I am of the firm belief that continuing to throw after the point in which fundamental mechanics break down is what will get the pitcher hurt sure as you are born. So if they saw something in his delivery then I agree, take him out regardless of no hitter. If they didn't and are just being slavish to the 100 pitch count then it was probably a bad idea. I wasn't watching so i can't say for sure.
I go over this with coaches on every team my son plays plays for. Pitch counts are a guide, I watch mechanics and when they go he is coming out regardless of pitch count. If I may stay up here on the soap box a few more seconds, I would hope all parents do the same. You aren't being "that dad", it's your kids arm. It's your responsibility, not the coaches.