It gives them the freedom to try things within the universe without risking breaking established characters/plot points. Plus, with a new character and setting, fans of the game will go in seeing something fresh. Im fine with it, and the wording in the yahoo news article make it seem like instead of this being a typical game adaptation, its a legitimate (canon) extension of the franchise. I totally get what youre feeling, but I think this works and even makes sense for the AC franchise, since the last few games have been about Abstergo expanding into games and films.