Although the developer’s recent statement that it isn't interested in any game that can’t develop into a franchise, Ubisoft has stated that the lengthy Assassin’s Creed tale will come to a planned end. Commenting on the series’ structure (in an interview with Eurogamer), Assassin’s Creed IV: Black Flag director Ashraf Ismail detailed that there are, essentially, two deciding teams in the Assassin’s Creed development process—at least where timelines are concerned.
“We have multiple development teams, then we have the brand team that sits on top and is filled with writers and designers concerned with the series’ overall arc,” he explained. “So there is an overall arc, and each iteration has its place inside [the Assassin’s Creed story arc].” Ismail went on to state that the aforementioned planned ending isn’t absolute; it will happen, but when it will happen remains up in the air—a schedule that is undoubtedly influenced by Ubisoft’s philosophy of annual releases.
In spite of Ismail’s claim that the Assassin’s Creed teams are “now able to seed stuff earlier and earlier in our games” in order to build plotlines proactively, the series’ structure has devolved to the point that, rather than asking when or how it will end, the more prevalent question seems to be, “How many obligatory releases will we be seeing before you call it quits on this mammoth of a cash cow?”
At least, I think so anyway.