You are still early in the process but it is never too early really to start thinking of the future and which path to go. Keep in mind that in the 3+years until he applies things can change. A program can go from being not so great to great, and vice versa. A cello teacher once regarded highly retires or doesn’t seem to have the spark any more. It will change, the kid may decide he really wants to study cello performance with X at Y school then suddenly say “nah, what was I thinking”. Here are my thoughts, they actually apply to most instruments.
-Getting exposure to music programs is huge (if it is possible, depends where you live and your family). I highly recommend youth orchestras and chamber music experience, given that ensemble playing is how 99% of musicians make their way. The big thing here is exposure to other kids and talking to them. The grapevine in the music world is a pretty amazing things, both with teachers and fellow students. Plus you also get a chance to see yourself compared to other kids, see where they are. That doesn’t mean that 'oh, go there, and just see how good the other kids are, and see if you are good enough". That isn’t the point, take it from me, at 14 it means very little unless you are still playing suzuki or something. I can tell you that kid everyone thought was hot at 14 may go nowhere (and in fact, given the odds with music, likely won’t). There was a kid in the youth symphony my son was in, who the people running it thought he was great, etc, etc, because he was technically advanced (more than a bit prodigy-ish). Kid never did anything in music. Meanwhile my son to them was a face in the crowd. It really is just to get an idea of playing, and also what in some ways to shoot for.
-Prep programs (if they exist in your area) can be valuable, they kind of recreate what a conservatory is like, you take lessons, take theory, orchestra, chamber, etc. It gives a taste of it, and again you get to see other kids and what they are doing, it can push you forward.
-This has been controversial on here, and while you don’t need to do these , summer programs and music festivals can make a big difference. Besides the getting to know other kids (that often extends well beyond the festival), it also is about getting to know people in the music word, specifically the people who are at those festivals who teach and coach. Sometimes it is well known, high level teachers, whom you might get to know and like as a teacher, but often it is also the people employed by the festival or those running it who talk about the music world and give insight. Along with what parents share on here (which also is valuable, there is noise on this forum too, but there is also a lot of insight). It also lets the kid know if they really want to do this, depending on the program (I am not a fan of the ones where it is like summer musical camp, like Interlochen, but that is just me, my view is it kind of dilutes the musical side. Then again, kids have gone there and thrived and they do bring in decent faculty and such, so that is a big YMMV).
It also gains the kid exposure in a pretty small world, gets them noticed. A teacher that works with them and likes them, or a coach there who sees the potential, can end up making a big difference down the road, they can recommend the kid to another teacher or recommend a school, or even want to teach the kid and can help get them a decent deal at a school.
Is this absolutely necessary? No.
-You should also be evaluating your son’s teacher. One of the big ones, does it seem like they know what is going on in the broader music world? Do they have knowledge of things like programs, how good the teachers are, what is required to get in there?
You would be surprised at how ignorant someone even in that world is. My son had a teacher through like 6th grade, who was a principal in a fairly big time regional orchestra. And it was incredible how little they knew (we realized this later, in retrospect),how uncurious they were, and how little they knew about what music schools were like today. They got into a well known conservatory in the middle 70’s, and they said they got serious in High School, got into this program, and right out of it got into the orchestra they are still in. Yet they didn’t know how much things had changed, what the level of playing was now (in an uncharitable moment, my son said they would have a hard time getting admitted to a top level conservatory playing the way they do now).
Teachers are an important resource, and if you feel the current teacher isn’t tuned into what is required to get into a good music program, or you feel they can’t take them to a high level, you may need to change. With our son he kind of had a goal, to get into a top prep program, and through a friend who was a well known musician and teacher (on a different instrument), we found someone.
One thing I will tell you, is to not let it overwhelm you (and it will, I promise that). Music is a tough, competitive thing, but what you think is the cats meow may not be, and one of the things you really have to do is believe in yourself (when I say you, I mean the student, though parents need to do that to). Take it from me, we knew very little of the music world, really nothing, and went on instinct, so try and not get discouraged or think like disaster lurks around every corner, it doesn’t.
. I also remember that at one of his audition days, he had his voice audition first, and then cello, and for the cello audition he decided he didn’t need to be so formal and pulled off his tie, unbuttoned his shirt a bit, rolled up his sleeves and headed off to audition on that fraught-with-danger first movement of Elgar and some more sensible Bach, with me trying not to hyperventilate over his audacity. And yes, they must have heard his potential because he was accepted on cello along with voice.