Good question, and actually something I have been considering.
In many ways this game will be anachronistic. Sorry, history simulationists!
One of those ways will be gender. While women likely won't be -totally- equal among mortals, they can own property, and such. Among the Supernaturals they are equals. Even oWoD did this with their historical settings. The reasoning is because...whether that Vampire or Werewolf or whatever has breasts or not...THEY CAN STILL CONTROL YOUR MIND OR MURDER YOU. So, at least among the supernaturals, they are equal. And among humans they are equal enough to allow for full rp, really.
Another anachronism, for instance, is age. Sure, irl people married really early and died really early, but we're not about to have a bunch of 16 year olds or whatever running around. So, folks are aged up. 18 age minimum, and people live longer. Plebs likely still die earlier due to life, of course, but it isn't as extreme.
Other anachronisms will just be some stuff moved around the Roman era. Like, the huge bathhouses weren't quite a thing yet, but I want them. And I want a big ass amphitheater even though it won't exist for about 600 years.
TLDR: History will be taken into account on a lot of stuff on the game, but not everything. Think of it more like playing in a movie or something of the era. Accurate in broad swathes to get the TONE down, but not the extreme details. I want the game to be as absolutely accessible as possible.