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.
Just a warning. Be aware that there is a very good chance that your child has at least 1 secret account that you don’t know about. They are called “Finsta” accounts on Instagram. My 2021 recently educated me on this and says every teen he knows has a secret social media account. This is apparently their attempt at hiding all their inappropriate stuff from adults (ill fated attempt I’m sure).
As to your initial question, a Twitter and Insta account are a good idea. Travel teams, showcase orgs, and even other players promote players through social media. The players I know do not create a new account for recruiting. Just have him use his regular “clean” account that you have access too and also start a Twitter acct. We did create a recruiting specific email account that incorporated his name. FirstLastBaseball@... I have access to it as well.