Aside from rare situations, such as gender based abilities for things like Rivalry, not really.
They still display the genders because you can concern yourself with a few situational things, like attacking a pokemon with cute charm as an ability, since it could trigger the effect.
You could also use the gender to know the right time to use the move attract. There's also the very situational Destiny Knot, but like the other stuff here, it requires the gender.
People post the gender most of the time on the RMT because they just use the team export feature on Pokemon Online most of the time, which also shows the genders of the pokemon.