Sorry for the hijack/piggyback. Most of this post isn't directed at you, but is more general ranting I need to say.
Producer/Project Manager with more than a dozen shipped titles across every major platform chiming in, including more than a couple with 8-digit budgets.
Different words get used with different context within the game industry that have a different flavor internally than it might to the general public. Words like "cost", "expensive", and "feature" can mean ENTIRELY different things depending on who you're talking to.
Something "costly" could mean it takes up a lot of bandwidth cycles within a game engine. Something "expensive" could mean that the project manager feels it's going to take a lot of work/effort/complexity during a particular release cycle. Something that's a feature could simply be a particular requested item from a designer (could also be called a story, an epic, an ask, an item, or whatever terminology that team is using at the time, often depending on the methodology the team is using for production).
On my current team, EVERYTHING that is requested by the EP, CD, or designers is a "feature" - regardless of what it is. Want a new animation? That's a feature. Want a new weapon type? Feature. New character archetype? Feature. Anything new that does not already exist within the game is a feature. Anything that is involved in the work necessary to create the feature is a task or subtask. A collection of features is either a theme or an epic (depending on the flavor of the collection).
This shorthand exists for teams of developers to work efficiently together. My production staff does all the wrangling so that the designers, engineers, artists, animators, and QA can do more work and still get home to their families while their kids are still awake.
Features all have costs. To the project. To the company. To my team members. If I have to make a call as to whether or not this product of entertainment includes a feature that leaves someone somewhere feeling a bit left out OR whether or not my development staff has to put in some weekends (a staff that includes significant numbers of women - many of whom are mothers or even grandmothers, mind you), then I'm going to want to weigh those costs against their work/life balance...and your personal feelings on the subject aren't nearly as important to me as the well-being of my team. Sorry if that offends. Actually, no I'm not.
Building out a new female character is just as difficult as creating a new <insert ANY adjective here> character. It means new concepts, models, rigging, storyline changes/additions, script changes, VO, and cut scene changes/additions. All of these additions now live in the game code alongside everything else, which might already be getting pretty crowded depending on what platforms you're delivering to. All of these additions make the code base larger and even more complex. All of these additions create bugs and technical debt that needs to first be found through additional QA (sorry guys, you're in this weekend because of the new character cut scenes) which then result in more work from the engineers (sorry guys, you're in next week till 10 PM mandatory because of the expected bugs from the new cut scene that QA will find over the weekend).
Because it's a console title that has a firm ship date (release date for AC5 is October 28th), you want to be submitted at least 8 weeks in advance to first party approvals (Microsoft, Sony, and Nintendo have to approve the code you want to put on their systems before they allow you to go to manufacturing - the RTM, or Release to Manufacturer is required before you can put your disk in a box). Once you have your approval, you have a scheduled and contracted run at one of the THREE approved manufacturers allowed to take your production run within the U.S. Miss your RTM date and too fucking bad - EA or Activision or Majesco or whoever has the time scheduled immediately after yours and they're not in a mood to negotiate with you for Q3/4 sales numbers. Once you DO get through your manufacture period, you have to get the units on the shelves at Target, BestBuy, Fry's, GameStop and anyone else you've contracted shelf space with. What? You think those end caps and front facing shelf spaces are just free and randomly put together by the store staffs? That's cute.
Bottom line to the above? AC5 is already well into alpha (feature complete) and possibly already into beta (asset complete) if they want to hit that late August/early Sept submission date they have looming ahead of them.
Best estimates I've heard from people I know at Ubi are that the additional female character was prototyped out very early but sidelined as the game itself is massive and requires an inordinate amount of work just to get the co-op working in the first place. They wanted to get back to the female character, but after costing her out, discovered it would take between 25-50 days of work to get her added in properly (that's the important word, by the way - will get back to it in a bit).
That 25-50 days isn't something you can just throw money and people at by the way. Character pipelines don't work that way. You can't start rescripting or animating new cut-scenes before you have the new rigged model. You can't rig the model till have the model. You can't build the model till have the concept art. You can't record the VO for the cut scenes and in-game play till have the script written. You have to then find the actress who will record the voice, and another actress to record the mocap.
All of this takes time. Time from someone already working late into the day/night and possibly on weekends. Because they're working on OTHER parts of the game. Because the game isn't done just because you saw a trailer at E3. Chances are the trailer wasn't done by ANYONE on the team and likely was outsourced out to a cinematics house.
The game date was likely set a year or more in advance by people setting up the contracts I mentioned above, so you may as well consider that date damn near sacred. That means to get the new character in, something had to give...or rather several somethings. Because unlike many other things in life, game development really can be zero-sum. To gain X cost of features, you have to give up X. But some execs don't think that way - they want X and don't want to give up shit. So they'll grind your team into the dirt to get there (if they're not all that worried about tech debt piling up or in keeping the team together after shipping). Other execs get it - at least to a point. They might ask for lower quality on this or that or may only "suggest" that you extend your team's hours.
However, most teams on AAA don't want to give up quality for anything. Why? Because that means lower Metacritic scores for one thing...a thing that most studio bonuses are inextricably intertwined with. Busted your ass for 2 years on a project and it's expected to bring in a 90 Metacritic so you can get your 20% IC bonus? Wait, you only got an 88% because some jackass kid who gets paid in pagecounts and free games decided you did a half-assed job on the animations for the female character compared to the male and the side-quests weren't involved enough (because your team threw those out to work on the female characters)...no bonus for you, sucker!
This whole subject makes my stomach turn to shit. I know a LOT of people on those teams. Good people. They WANT to bring in more features - female characters definitely is part of that. They hate being called sexist. They hate upper management telling them estimates for their work that they KNOW is wrong ("only a couple of days worth of animations" might as well read "fuck you every other animator who can't do as well as I think I can as fast as I can on new tech").
I know very few devs who are true asshats (yeah, lots of brilliant jerks, a handful of outright assholes, most are just great people who do this for love, not money - they could stop making games and go build tax software tomorrow and double their paychecks in some cases). It's personal when I see people I know and respect called liars or sexist.
I hope the post helped you see a bit into our lives as much as it helped me to get some of this off my chest.
