Do we actually get any dialogue that any class is gendered in the comic? since I do remember it being implied to be true for some classes, but I can’t remember from where.
I also think there’s no real reason for any class to be gendered, and unless someone said something, the sample size of session we see is so small that it’s not like we can confirm if a class is exclusive by just two or three people playing the role.
though against the “gender doesn’t matter” bit, assigning classes gender roles then assigning people them against that role could be good fuel for a character’s personal journey to be about their relationship with gender, either their own or their perception of it.