Advocates of modern gender theory claim to believe that gender and sex are different things, but also believe that every case of sex segregation should actually be analyzed at the level of gender.
Female sports are separated from male sports specifically because the very best females cannot beat the very best males in most physical competitions. If female segregated sports should exist, then the separation only makes sense if the distinction is made at the sex level (where the physical difference in capability is manifest) as opposed to the gender level.
If not, then as Nick suggests we can abandon any segregation between male and female sports, and females can simply be nearly universally excluded by capability differences.