Acutually, the centuries old version of "feminism" wouldn't be anything close to the modern sense and some might even find it offensive. Trying to say that because there were women involved in French revolutionary mob culture doesn't by association mean they were anything like the modern version of the liberated woman, or that they were even all that independent. Indeed one of the big issues with feminism has always been that a lot of women tend to approve of, or gravitate towards, traditional, subservient roles, and indeed a lot of women actually worked against social reforms
in order to avoid responsibility. Indeed this is one of the big reasons why you see so much conflict within the feminist movement with some elements seeking to pretty much strike down or erase anything traditionally feminine, or deny the existence of certain instincts. At this time period in particular you wouldn't exactly be seeing a push for anything equivalent to full blown sufferage, which got attention when it happened, because it was unprecedented.
Now, another point to consider when you look back at women who are remembered for being active during various historical periods it's important to note that they are famous for being an extreme exception, not an example of what everyone was doing. Because there was Joan Of Arc did not mean you had scads of women riding around as knights for example. The limited nature of the exceptions is a big part of WHY female player characters don't make sense in these periods because after all, if there were more it would have been really noteworthy. It would be difficult to
acknowledge in a work claiming that history is viewed as it is in the real world because nobody knows all off this stuff happened, that there were incredibly lethal women getting involved in the midst of these events. "Assassin's Creed: Liberation" gets around this problem to an extent by making it clear that this never really happened, at least not as presented, as your basically experiencing what is a Templar propaganda piece about Assassins. As a result "Liberation" doesn't have to worry too much about where it fits into things and why we never heard of this person doing all of this stuff. "Unity" on the other hand is part of the main continuity and progressing the main storyline in a way "Liberation" given it's rather roundabout justification arguably did not, as a result they have to be a little more careful.
The thing to understand is that Assassin's Creed is trying to be a hidden alternate history, as opposed to a flat steampunk or historically based pure fantasy setting where the alternative history is obvious to everyone in the world. That somewhat limits their options, though they can get creative with the spin offs like they did with "Liberation". As crazy as they get, in the end you generally have to leave things so the real world history would still be what people believe.
What's more I think people underestimate the investment in resources in creating alternate player models and whole new dialogues (both ways) in a game like Assassin's Creed. It's not a matter of just re-skinning if they want to do it right for full on game protagonist status. If they decide to make the female model move in a feminine fashion that requires whole new animation sets for every interaction in the game. What's more if she's say a head shorter than the male model, that means every single jump, climbing area, and parkour possibility has to be re-designed entirely so it will line up properly with the models. In some games where there isn't a lot of spoken dialogue and the world interactions are limited it's no big deal. In a lot of MMOs you don't generally climb around on things or whatever, your lucky if the game has a double jump, and most MMOs don't even create sitting animations for chairs because it's too much work. As a result a dozen different sized races with male and female options is no big thing. When it comes to voicework, it's important to note that Bioware, the guys who everyone is generally thinking of when it comes to how a game "should be" stands out because they put a huge amount of effort into it. As early EA exposes on "The Old Republic Online" pointed out, Bioware's sound design is incredible, on the other hand it came at the expense of the rest of the game, and apparently was a big part of why they were so late and so over budget in the end.
That said, people are overreacting, which is why I offer some balance by presenting another possible side to this, while not really giving two shakes of a rat's tail. Ubisoft has been one of the more diverse developers out there and all the flak thrown at them is "social justice warriors" biting the hand that feeds them, rather literally. I mean Ubisoft already did a whole spin off game, carefully written to allow a female character in this kind of game play, specifically for the people who demanded it. What's more the game sold to their satisfaction apparently so they will probably eventually do more in a similar vein. It's not like Ubisoft is slighting anyone here, as nobody is entitled to representation, the creators had a vision, and they have gone with it. There is no reason why they should have to justify themselves because they had a female lead in another game to begin with.
I'll also say that while many people might not see it, this kind of garbage is how video gaming gets ruined. It leads to the whole "design by committee" mentality where creators become slaves to what they are told a game has to be and what changes need to be made to it to avoid attacks and "appeal to the broadest possible audience" as opposed to following a vision and being good in their own right. To me these complaints smack of someone attacking say "The Three Musketeers" because it involved four white dudes as the heroes. Nowadays if someone brought that story up, these kinds of incidents would mean that the publisher wound demand they insert a woman and an ethnic minority for the sake of inclusion and to avoid upsetting anyone... which is fundamentally what people seem to be demanding here (albeit this particular article didn't bring up the race issue which some others have).