I personally want to roleplay LOTS of all kind of scfi stereotypes, no matter my personal values, I will go to extremes to play each as true to original as possible.
I don't know how many others will try the same but I'm not only one.
Sure based on portraits we can't notice difference between alien males and females, and even in some alien names.
But I'm sure Emperor Mercedes Romero doesn't sound right, right?
Then why don't we get ability to change titles and Empress Mercedes Romero can finally be happy.
That trick might work, until my HUMAN Empress (insert_female_name) looks like a guy. <- that's a major immersion breaker!
So I repeat best solution I saw so far, probably make it policy with purely cosmetic effect:
Strongly Matriarchal: only females can rule and be leaders(so every position will be female) <- maybe your species doesn't have other gender
Lightly Matriarchal: only females can rule(only the empire's ruler is female, all other positions are open to both men and women) <- maybe you are a space bug with a Queen because that has never been done before
Equality: both men and women can rule <- maybe you are PC
Lightly Patriarchical: only males can rule(only the empire's ruler is male, all other positions are open to both men and women) <- maybe you are a bit sexist
Strongly Patriarchal: only males can rule and be leaders(so every position will be male) <- maybe you never left the Middle Ages
There is like 0.08% chance of something like this being in game on release day, but I have great hope that something affecting gender roles to help people roleplay vast possibilities of space comes in some future patch.