Religion was not the sole reason girls were originally excluded from education. And like race, religion was also not the only original reason that when group schooling was made available to girls and women it was in segregated schools.

https://en.wikipedia.org/wiki/Single-sex_education

And not all Catholic schools segregate by sex.

The discussion is about religion and how it is silly to say that church can ignore culture around. Segregated higher ed is a random example I thought where catholicism got on with the times (I thought it was a church thing). Another example is contraceptive use.

I didn't mention discrimination against women at all, I don't know enough about catholicism to say if it was a thing.