Assassin’s Creed: Mirage has been available for about a month and a half now, but Ubisoft is certainly not done with the title yet. The developer is working on a free Major update for the game and the intention is that it will be made available in early December.
This update will provide the game with a New Game+ mode, which allows you to start over after completing the title, but while retaining all the unlocked content. Ubisoft will also add a permadeath mode with the upcoming update.
Exactly when the update will appear has not yet been announced.