I looked into this a couple years ago when I was on staff at a D1 school. Near as I can tell the "local" part of it can be gamed in any number of ways and the whole set of rules around it is extremely loose.
Regardless it's clear that this isn't an issue of rules or any potential harm to an athlete, there's a collection of keyboard weirdos that are just looking to justify hate for Brosnan.
Generational talents have dedicated an exceptional amount of trust and energy towards a coach, coach takes an awesome job opportunity but still fulfills the remainder of his side of the coaching relationship to said generational talents. Santos get's better prepared athletes when they show up to Stanford, everybody wins.
I'm not a creep who obsesses over what high schoolers are doing so I don't know/care if they are still running for NP this outdoor season but given the way CIF works for outdoors that even that doesn't seem like a big deal. With no divisions it's damn near impossible for NP to win a team state title so the Young's aren't giving up a team requirement. The gauntlet of championships that a SS section athlete has to go through to even get to CIF finals is stupid and definitely not good for athlete development. If you've already got a scholarship and want to prioritize long term development the rational move is to not care about CIF.
In the age of the portal is they want to end up at UCLA they are gonna end up at UCLA, but I would assume Stanford is still more enticing as a legitimate team contender for XC, better education, and imo better training environment.