Lol. This video has been posted a lot of times, mate. Trust me, if a Surface device is on the works, it will not be leaked out. Look at the Microsoft Device launch where the Lumia 950/XLs are officially introduced. Nobody expected MS to come out with the Surface Book, and last year they came out with the Studio.
Trust me, Microsoft is playing the hype-game. I just hope that the Surface phone, if it ever becomes a reality, will not be plagued with software problems like the 950/XLs had during launch. Windows Phones were already having a bad reputation pre-W10M, and the release of the Lumia 950/XL with all their launch day bugs were the final nail in the coffin for consumers, causing many people to lose interest in W10M altogether.