That time round the excuse was that a woman in a dungeon would be fundamentally ridiculous (a dragon in a dungeon being simple historical fact, of course). This time it's because it would be too hard to animate a female character.
Even if we leave aside the fact that this point is only true if you make assumptions which dig Ubisoft even deeper into a pet of thoughtless sexism - a woman can only be significantly more difficult to animate than a man if your idea of a woman necessarily includes long flowing hair and/or a large chest - the sheer stupidity of believing the excuse would wash is staggering, and revealing all on its own. The only way arguments of such coma-inducing ineptitude ever get released beyond the ids of orangutans is when no-one the argument is being deployed against has been allowed within a hundred yards of the discussion. It is as obvious a demonstration of the need for inclusion as anything you're likely to see outside of a George Will column. Or this:
People, please, I'm begging you. If you're facing down a storm of controversy over gender issues, talk to actual women before you draft your response. Hell, you could even talk to women before you finish designing your game, and head this crap off at the pass. But baby steps, I guess. Not like this is twenty fucking fourteen, or anything.
Update: A friend of mine who makes a living creating video games had chimed in to explain that, whilst "aminating wimminz is hard" is a shitty reason to not include female characters, it isn't quite as ridiculous as I was thinking. To quote the man:
Ubisoft's claim is almost certainly a valid one. To properly do a female character justice does require a substantial amount more in terms of animation resources. It depends on the game engine, but at the very least I'd imagine you'd be looking at 50% more individual animations. Running male anims on a female character can work but often produces very odd-looking results due to the differing body proportions. Sharing the animations can work (I'm pretty sure Mass Effect does a lot of that) but to get things looking 'right' probably does require new animations. Ultimately it's a cost issue: adding female characters doesn't actually add much in terms of gameplay but it can double the animation requirements. Now, personally, I think that's a cost worth paying and I find it hard to believe Ubisoft can't afford it, but as a reason for not implementing them, it is valid.