Was thinking if we were to do this for my son (2023). He has his own private account on Instagram right now. It is private to his friends and our family. I know that nothing is really "private" thanks to screen shots. So we have already had that conversation about posting stuff. Good thing is that my wife monitors everything he posts.
If we were going to do something to promote baseball i would imagine it would be an account that I would try to control jointly with him. It would be for baseball only. Nothing outside of baseball pictures and videos would be posted on that.
It was so much easier back in my playing days where when a coach wanted to contact you it was via mail or a phone call.
You might want to think through that because coaches now are checking to see if he has another account. We had several ask my son if he had any multiple accounts. It could be considered a trust thing. I would just have him watch what he puts on it. It is part of the growing up process. They want you to have multiple social media sites and it was amazing how many followed my son on his social media. Talking to coaches they learn a lot through a kid's social media interactions that no one will ever tell them.