About 10 years ago the question on this site would have been - can you believe coach had him throw 140 pitches. Times have changed when a kid throwing 90=100 pitches generates a question about "overuse".
Of course 10 years ago there was zero pitching rules in HS and folks out here were passionately arguing "kids don't throw enough anymore".
I think it has become common wisdom (sense) that pitchers should pitch with a plan for how many pitches they will make and on what schedule. We did this with 11 and 12 year olds way back when.
What happened in this scenario is a bad idea. If he ended up with 15 or more pitches in game 2 and started closing in on 125 for the day then he would have been way out of bounds.