“[The issue of slavery is] something we’ve been very aware of. Everybody had slaves at that point; the first groups who rallied around emancipation didn’t come around until 1787 – largely driven by Benjamin Franklin funnily enough. That was very much after our game and slavery was maintained in culture. We feel that kind of a subject deserves a certain amount attention because it’s so serious and it needs to be treated with utmost respect. We’re definitely not going to shy away from it in terms of not showing it.” - ACIII Lead Writer Matt Turner

The Assassin's Creed series definitely takes history seriously, so I'm sure this element of history is going to be handled delicately. Important for it to be recognized in the game, but it has to be given the proper respect.