If you define pre-existing condition as a condition you had prior to buying a policy, then yes, being a woman is a pre-existing condition. Other than that little logical error, I’m with them.
Is having a uterus a pre-existing condition?
The insurance companies seem to think so, says the National Women's Law Center, an advocacy group for women's legal rights that is on a mission to end unfair insurance company practices toward women. And it believes it's making some headway
Source: Law.com - Advocates Say Being a Woman Is Not a 'Pre-Existing Condition'