https://www.thecrimson.com/article/2018/9/10/stanford-admit-rates/
The REA stats will not help you to gauge your son’s chances, anyway. Most recruited athletes apply early, and that drives the acceptance rate up. The higher rate does not mean that an unhooked applicant in the same pool has any advantage as compared to RD.
Also, FYI, the word “ivy” in Ivy League is not an acronym (“IV”) - it’s the plant that grows on the walls of stately old buildings.
The deluge of mail from Ivies, UChicago, Stanford, etc. means nothing. Really, literally nothing. Students with lower stats than your son’s, who have virtually no chance of getting into these schools, still get mail from them. These schools compete for rankings based, in part, on their acceptance rates. The more applications they can reject, the better for them. So they want lots of applications. That is all it means.
That said, your son does have a strong record. I’m sure he’ll end up with some good UC options, and he can probably get into other excellent “reach” schools as well. You are well aware that the odds are against him at Stanford. Has he considered Harvey Mudd? He sounds like the kind of well-rounded student they are looking for, and it’s a top-notch CS school. How about Rice?
What does he want in a college experience? Your phrasing is all about where “we” want him to apply - how does he feel about his options?