Ubisoft confirmed the leak today with an image posted to Twitter and a sentence that it's hard not to read without adding an exasperated sigh: from the publisher "Assassin's Creed Mirage is the next Assassin's Creed game."
They always leak, and this one happened just over a week before Ubisoft Forward, the livestream event where the official Assassin's Creed Mirage reveal is set to take place. This will take place on Saturday, September 10.
Bloomberg's Jason Schreier reports that his source isn't entirely sure about the latest leak's details, but we can safely say that Assassin's Creed Mirage is set in Baghdad and stars Basim Ibn Ishaq (aka Loki), and that it most likely began as Valhalla DLC, as Schreier reported in February.
The two reports also agree that Mirage will be a "return to basics" for Assassin's Creed, with a focus on stealth rather than RPG-style levelling and dialogue options. If that's the case, the teaser image's classic Assassin's Creed hooded assassin look is appropriate. But it's a rather amusing scene: Good composition in terms of visual design, but that is the least shrouded assassin ever. Why isn't anyone looking up at the guy in the air?
At Ubisoft Forward, we'll learn more about Mirage. At the show, we may also hear about Assassin's Creed Infinity, but Ubisoft has stated that Mirage is the next Assassin's Creed game. It may stay quiet about Infinity while it simmers now that it has a new AC game to talk about. (However, I'm sure more information about Infinity will emerge in due course.)