It's possible we have a name for a new Assassin's Creed title in the works atafter a document shows a spread of promotional work, but it's also possible this was the name internally for Black Flag.
The reason this could amount to nothing is because the 'Golden Age' is likely referring to the 'golden age of piracy' that was the main theme of Assassin's Creed IV: Black Flag. The images are also 'piratey'.
The 'leak' is part of aon their Graduate Program, and then proceeds to boast about their portfolio. We do know that Ubisoft has other Assassin's Creed titles in the works, with one codenamed Victory and another said to be targeting Xbox 360 and PS3, much like Rogue did.
Most likely this is an old photo of Ubisoft working on Assassin's Creed IV: Black Flag.