Interesting discussion...couple of thoughts. Our pitching coach (PC)calls the pitches. Pitcher has the approved authority to shake it off if he see's something differently. Maybe he is having trouble feeling a pitch or hitting his spots. The discussion between the PC and pitcher regarding those pitches he shakes off occurs between innings or if the PC see him shaking off more than occasionally he will call time and go figure out what the issue is.
My personal opinion is that this provides the best teaching environment with the least amount of pressure on the players. In HS we want the pitcher and catchers to focus on execution and not become overwhelmed with strategy. If we call a fastball on 0-2 and it leaks over the plate and gets taken for a ride the pitcher learns that they need to improve location execution and they can do that. The pitcher and the catcher learn what we believe (assuming we are as smart as we think we are) SHOULD be thrown in a given situation at a given time of the game against a given batter. As they grow if they continue to play they will experience different philosophies from aggressive to overly careful and some will work for them and they will look like a Cy Young winner and some will not and they will begin to recognize what works for them. If the PC is doing their job they are also explaining the "Why" of the pitch selection.
Example: Last week we were coming through the line up the 2nd time and the pitcher was facing the 4 hitter with 2 outs and no one on base in a 0-0 game. Four hitter is 6'3" 225 and is not a bit fat, drove a low outside 1st pitch fastball into center for a single in the first. BUT he is also aggressive and likes to hit early in the count. This time the PC works speeds and achieved a 3-2 count and called a curve in the dirt. Ball bounced in the dirt, catcher blocked it batter swung so hard he almost fell, tagged out happy ending. In between innings PC told the pitcher why this was the right pitch..."In my mind that was an intentional walk with a high upside, what we did not want to do was give 4 a pitch he could drive for a double or worse with 2 outs". Once the pitcher has heard enough "Whys" they are thinking the pitch before the call is made.
When they are successful and they learn, when they fail they learn and at the end of the day they get accolades when they pitch well and the PC is to blame if they get hit hard...