It isn't a hoax, or some web rumour, it does exist, and here's some chap playing it (under lots of lights and not with the best camera) to prove it. From what you can see, it looks pretty decent to me. Come on Activision, release some files! The truth is out there now.
The sad news is, no matter how good the game really is, or how it sells, with Nihilistic focusing on mobile gaming from now, it probably won't get the DLC love that this series enjoys and the game will need to keep the fans coming back.