The scuttlebutt I heard on him is that he opposed using machine learning and artificial intelligence techniques for search, specifically deep neural networks.

The scuttlebutt I heard on him is that he opposed using machine learning and artificial intelligence techniques for search, specifically deep neural networks. I can understand his opposition, Google search results have been monotonically declining in quality recently in my opinion. I wouldn't be surprised if this is a polite way to sweep him out of the way. It's pretty much a golden parachute if so. This is of course all speculation and hearsay based on what I heard about him a few months ago.