Zachary Amaranth said:
It's kind of awkward seeing Connor in 3, considering the time period. If you can include him (as he was poortrayed in a narrative sense), you can include a black person in France. It doesn't matter if they're not native to the land. Hell, France even had black representatives to their contemporary national convention.
Further, if you can have a slave be an assassin (Liberation, Aveline's mentor), there is no excuse here.
Honestly, the excuses being made are a bigger issue than the lack of any diversity in the game.
As has been mentioned by others, there is also Thomas Dumas, a half black Haitian who became a French General during the revolution, and whose son would eventually write both the Three Musketeers and the Count of Monte Cristo. Given Ubisoft's penchant for throwing historical figures at us by the handful, I wouldn't be surprised if this guy is actually a character in the game, or at least a cameo.
There was also, as mecegirl mentioned, Joseph Bologne, the "black Mozart" who was also the leader of France's first all black French Regiment, which means there were at least 3-5,000 black soldiers marching around France during the revolution, and that was just for an all volunteer regiment of black people that wanted to serve their country.
As far as other groups, as FalseProphet mentioned, one of the most high profile assassinations involved a woman stabbing one of the leaders of the French revolution, Jean Paul Marat, to death in his tub, which given Ubisoft's setup of how pervasive the whole Assassin and Templar thing is, she will probably end up being a secret assassin or Templar operative, considering that AC2 basically hints that every major assassination in world history was carried out by one of the two groups.
Historical accuracy isn't a terrible argument to use, but you actually have to know something about history if people are going to make this arguement, just assuming that anything that happened before the 20th century means that it must be completely homogenous both racially and with regards to gender, is going to backfire if you aren't careful.
Not that it really matters in this case, since this is AC we are talking about, where literally every assassin in world history was part of a conspiracy involving ancient aliens. That, and the whole world takes place inside a matrix-like video game anyway, to the point that in AC4 there are log entries that flatout admit that they edited in buildings and locations, that shouldn't be there historically in order to make the locations more visually compelling and interesting to explore, they also take a number of liberties with historical events, and put historical figures in places and situations that they obviously never were in.
So yeah, the historical argument kind of falls flat in a series that comes out and admits in-game that they are willing to throw historical accuracy to the curb in order to make the animus simulation more interesting.
More OT: no, I don't think Jim went too far, since he never actually called the game out for being racist or sexist (nice emotional manipulation in the title by the way), so I'm willing to give Jim the benefit of the doubt that he was more making a joke about the assassin's all looking very similar, rather than trying to claim the game is blatantly racist, or whatever you are trying to paint his statement as. Yes, Jim has talked about gender and racial imbalance in games in the past, but he has never given any indication that he thinks this is some blatantly racist or sexist issue that he demands be changed, he wants diversity, but he has never indicated that he thinks that developers are terrible people just because they aren't giving him what he wants.