The rules are fluid. Teams and individuals have been allowed to compete under circumstances that seemed to violate Nike’s published rules. They were allowed to compete even though they were ineligible to compete for their high school team. There are a few teams this year that could split their runners evenly and be close to qualifying but nobody would be willing to take that chance unless they were nearly certain.
What about large school districts that have multiple high schools? What about states with open enrollment? What about adding other athletes to a current team from within the school if the state doesn’t allow dual sports? These things all violate Nike’s rules but seem to happen. Unless another team complains about a situation, Nike wouldn’t know or care. They probably welcome the additional entrants and higher quality competition.