May I ask more proof do you need, taylor? Jay Olivia says its exists, Ray Fisher says it exists, Jason Momoa says its exists, Cirian Hinds says it exists, Kevin Smith says it exists, and Zack Snyder himself says it exists, we've also seen stills, pre-viz, and storyboards. It exists.
That video of him talking out his butt at some autograph table at a convention doesn't prove anything. A director's cut is a complete version of the movie including all special effects and the director's approved editing.