The Sacramento Bee reports that three female athletes--two field hockey players and one who wrestles and plays rugby--have sued UC Davis to challenge its distribution of athletic opportunities and scholarships.
Davis's proportionality score is very close to the generally-accepted "within 5%" benchmark for compliance with prong one: they have a student population that is 55.5% female and they offer 50.25% of athletic opportunities to women. Also, Davis reports that 50.47% of its athletic scholarships go female athletes, which complies with the requirement that percentage of scholarship dollars for women must be within 1% of the percentage of female athletes. It appears that attorneys are arguing that a ~5% disparity in participation opportunities does not amount to substantial compliance. All three athletes play on club teams that want to compete as varsity. So they must be claiming that in light of the proportionality disparity, the university's failure to elevate them to varsity violates all three compliance prongs.
The article also notes that the wrestler-plaintiff already has a pending lawsuit against UC Davis challenging the athletic director's decision to dismiss three female wrestlers from the team. You may recall that earlier this year, UC Davis settled a lawsuit by the wrestling coach, who claimed he was fired in retaliation for objecting to the AD's decision. It was reported then that the female wrestlers complained unsuccessfully to OCR, which found that they did not follow proper procedures in petitioning for a women's wrestling team of their own and that such a team lacked potential participants and prospects for extramural competition.
If this is all that OCR said, I can see why one of the disappointed wrestlers is now bringing a lawsuit. OCR's decision only addresses why UC Davis did not have to create a separate women's wrestling team, not whether it was proper to dismiss female wrestlers from the existing team. As the 4th Circuit held in Mercer v. Duke University, you don't have to let women play contact sports with men, but if you choose to, you can't discriminate against them on the basis of sex.
For a prior post noting the emergence of women's wrestling, see here.