When my kids were in HS in NorCal you could choose a different school in your district so long as it wasn't impacted -- IOW, it had to have room. However, coaches were not allowed to recruit, and they seemed to take that very seriously. When my kid was in the 8th grade we were at a HS baseball game and started talking to the school's varsity basketball coach. After a couple minutes he said he couldn't talk to my kid because someone might see and report it, even though he was already set to go to that school.
The coaches can’t recruit. But the kids learn the ropes by word of mouth. Plus they’re seeing in the local newspaper who’s winning in what sports.