Google is an enormous company which operates flatter than you’d expect for an organization of its size. It’s entirely possible that someone from Google was involved in organizing this (i.e. booking the venue) without having buy-in from leadership. Once leadership became aware after being asked about it, they may have shut the whole thing down because they knew the optics would be bad.
I’m not convinced he really believes that OpenAI is going to roll out AGI in the next ten years, but I’m completely sure he’s determined that it’s a good marketing strategy to make people believe that he believes it.