Hassabis moves to Chair of Google DeepMind as Koray Kavukcuoglu takes over Gemini development and Jeff Dean leaves Alphabet

Sources: CEO message, discussion, Jeff Dean discussion
Summary: Sundar Pichai published a message to Google DeepMind employees stating that Demis Hassabis moves to Chair of Google DeepMind and that Koray Kavukcuoglu takes over Gemini model development, Frontier AI research, and the Gemini app and developer teams, which now report to Kavukcuoglu rather than to Hassabis. The same message states that Jeff Dean and Sanjay Ghemawat leave Alphabet after 27 years to found an independent public benefit corporation for machine learning, science and engineering, with Google as a founding investor and Cloud partner. Both facts come from that single message, which is carried here as the primary source rather than the wire reports that reached Hacker News first.
Why it matters: The roadmap owner for the Gemini models most teams build against changes hands.
Follow-up: Track whether the reporting change produces a visible shift in Gemini release cadence or model deprecation policy.