Will they take any alternate testing? Under your district's policy my HG kid wouldn't qualify. MY DD scored a 149 on WISC-IV (99.9th percentile) and 99th percentile on the Naglieri but she only scored above the 98th percentile in one area on the CoGat. As many people on this forum have discussed, CoGAT is a group administered achievement test. It can miss a lot of kids.
The gifted program I attended as a kid had two tests. The first one was a group test, and then people who got passing or borderline scores were re-tested individually with a psychologist.
That said, those days are probably gone.
I suppose the answer to your question is "It depends." If the school gets more money for gifted students, then they might be willing to take other scores. If not, it would be a harder argument.
Schools have their own unique rules, I guess. It's odd to think that a school might discount a score of 149 on one of the major IQ tests in favor of a group test. Oh well.