I appreciate your thoughtful and detailed response.
I think that the suit would be backed by a major right wing/Christian organization and they would be court-shopping from Day One. I don't think they would bring the strongest case in the 9th Circuit. I think they would bring it in the 5th or 11th.
The case against the MHSAA (for playing girls' seasons in the wrong time of year) was brought by female athletes who had long since graduated by the time it made it to the Supreme Court, so I think that a harmed athlete could be the plaintiff while in high school and it would stretch out for years after that, but the case would continue.
I absolutely think that missing out on the State Championships, or a podium position is sufficient harm to say that a court should consider whether one has been denied the BENEFITS of participation. Participating is not the only benefit, in and of itself. Earning the rightful gains of one's work is a benefit, as I see it.
I do think that the strongest arguments against this case are your points #1 and #2. I acknowledge that.
I think the strongest case the other way is the simple constitution of the current court, if you can get a case in front of it.
I think today's court would rule that "the law, as written, says 'sex.' If the Legislature intends to mean 'gender,' a new law must be passed."