We're not there yet, but from my playing experience

that seems to be about the age where you might have a tournament or two where you're playing 9 with re-entry rules. I wouldn't be that bothered by doing that in the championship game only if my kid had opportunities to play in earlier round games. (Doing it for the whole tournament without communicating that before parents are traveling and/or taking on expenses would be bush league.)

I think adding kids for late season tournaments is kind of part of the game at some point. That feels a little young for me, though. It's one thing to do it to account for vacation schedules and maybe someone gets some innings cut because of it. It's another to just wholly replace kids that have been playing hard all year. But conceptually I don't have a problem with a new kid who may play for you the next season play and take some innings. And if it's going to mean regulars aren't going to play, depending on the circumstances and travel involved, I can see where some communication to parents would be the right move.

Talking to the team about the fall season is inevitable. Sure it may not feel good to be that kid in that moment. But that seems like those things would naturally be discussed in those settings

The things that bother me more are the snide comments to show up a kid and not talking to the kid about the demotion. I recognize that kind of coach, and in my experience that guy isn't coaching. His primary job should be talking to the kids and teaching them how to get better and develop.

That said, my coach didn't bat the entire lineup with free substitution rules until the 15U county and city tournament and a one-off 12U post-season tournament. Even while other teams were playing 9 and even in county tournaments that we won in 14U and that we nearly won in 13U in a season where we beat every team in the league 1 or 2 times. We didn't leave the ordinary development league until 16U. He cared primarily about player development. And was excellent with the kids. We formed the core of a varsity team that lost a 2-1 game to the DII state champs in the regional finals and lost a 1-0 game to the eventual DI state champs. So it's hard to say that approached deprived us of competition needed to excel.

My brother's coach played 9 in tournaments at a younger age than I did, and he added kids late in late tournaments to build relationships for the next year. But they also dealt with vacation schedules to work around, too. And he wasn't overloading the roster to totally deprive playing time of regulars. But some kids could've had some innings cut.

My varsity high school resembled the guy you're talking about. I don't think there's a single player who improved in any aspect of his game because of anything the coach did. But he had excellent youth development feeding the high school and his brother played in the pros, so he thought he was a coaching wizard.

The head coach and I (just finished 10U) are in no real hurry to play select ball for all these reasons. We'll make the move whenever we feel it'll be better for our kids' development to improve the competition they face. And the first step would probably be to play in the Athletic league of the local developmental league that permits teams to bat 9 at a younger age that self-selects into the higher quality teams. Our team probably isn't deep enough to do that without getting creamed. At some point it'll be worth it for our kids to do that anyway to improve the competition they face. But they're still young to suck the joy out of playing ball.