While I've shared my personal position, let me sum up how I'd sum up your son's POV.
1. He visited and engaged USNA as part of NASS. Different than a CVW, and a very nice opportunity to gain a bit of a feel, if not the real deal.
2. He liked his time at USNA, applied, and has been provided LOA, nomination, and consequent offer of appointment.
3. He has announced his sole plan to accept said offer. In fact, to date, has not even applied to a plan B institution.
4. Beyond being "good," stay diligent in studying, and not getting seriously injured or sick, nothing more to be done. It's both Christmas Eve in the world, and similarly so for I Day, 2013. The stockings are hung by the chimney with care, filled with a BFE and a response sheet to be mailed.
5. He is "contracted" and playing a key role with high level team and 'mates and school depending (or unit) upon him. He implicitly or explicitly determined that he wanted to be part of that group, acknowledging that he could be counted on to be at every practice, match, etc. He's a man of his word.
6. He has indicated that a CVW, while nice and informative, will not change his heart nor his mind. In terms of his decision, it will make no difference.
7. However, missing a key game or two might well make a big difference for his mates and his relationship with his team and coach going forward. This is too important to treat with out careful consideration, as just another game. It's not from the sounds of it.
8. He's been driving the ship up to this point in fine fashion, making good decisions. I'd let him continue doing so.
9. As for Mama visiting Naptown? That will come very soon, with a rush of opportunities over the coming years. It's not going away. Still lots of shops with lots of stuff to shop for.
10. Most candidates do not attend a CVW. They matriculate, survive, and thrive. This is the no-brainer of all-time. I'd say, it's time to play hockey!
And make sure he wears his mask, eye protection, etc.