There's no doubt that Ubisoft has been victim of many leaks through the years. Pretty much every Assassin's Creed game seems to be revealed before the French studio intends to, for instance. That might be the reason why they decided to "leak" a new game themselves.
You'll come across a very interesting side-mission when playing Watch Dogs 2. It starts with you overhearing a phone call where two guys are talking about a teaser trailer they've made. The guy on the other end is worried as many of their projects have leaked early. He mentions "Syndicate, Unity and Osiris" specifically. That's obviously referencing the Assassin's Creed games, so it caught our attention when a mission to see this mysterious trailer of theirs popped up. Where did we have to go to see it? Ubisoft San Francisco's office of course.
Hacking our way into their office revealed lots of game art and the previously mentioned teaser. Some of the art pieces are from already released Assassin's Creed games, but there's also a few we've never seen before. We see some German-looking soldiers and red banners, which indicate a World War 2 setting. It could just be assets from Assassin's Creed: Unity, but that's not the case for the trailer. Is it possible that Ubisoft just revealed a new game, or are they making fun of us taking stuff like this and turning it into news? Either way: well played, Ubisoft.

