Great news. Beware though, a simple phone call with a coach rarely is executed on first try. Usually, the recruit, maybe like your son gets a message to call Coach Smith at Big State, and is provided the coach's cell. On average it usually took my son 2-3 attempts, over a few days, to reach the coach. Early on son would get frustrated. I'd say, "These are busy guys, getting lots of phone calls, they have families, practices, just keep calling don't take it personally. Keep calling."
Probably the first of many calls, the bulk of which you won't even know about by the time your son commits somewhere. If the process keeps rolling along you'll be talking with your son one day and he will say, "Oh yeah, forgot to tell you, I spoke with Coach Jones LAST WEEK. I finally got him during my lunch period at school. Call went well...............blah, blah." This is where the rule of 3 comes in handy for him. He will be in a rush between classes, these calls usually don't last more than 5-mins anyway. If he has his "go to" 3 questions in his mind, he will always be ready to execute.
And why 3? When your son gets on phone he will get excited and maybe nervous or flustered. All the rehearsing (which you should be doing with him btw) will go out window early on with these calls. Most teens can remember 3 things in these situations!
Some great question examples above for you son by 2019 and SO. But your son should always engage with the rule of 3, minimum.
Keep us posted!