The former AMD designer and Chief Architect of the ZEN architecture, Jim Keller, left AMD about a year ago. In the meantime, he joined Tesla to work on AI hardware as head of the department. Latest reports tell us that he left Tesla to fully focus on designing processors at another company. While there's no official statement, good sources suggest that he'd be joining Intel.
Keller was not only responsible for the recent ZEN architecture, he was also leading the development of AMD's still-upcoming ARM-based K12 CPU and the older K8 and K7 microarchitecture. In 2016 he left AMD to join Apple, during those 6 years he worked on the A4 and A5 sockets. Jim Keller is said to be one of the most important and popular CPU-architects.
Jim Keller is not the first to join Intel as former employee at AMD, also Raja Koduri (chief architect RTG) joined Intel a while back. There's some speculation that Chris Hook, who was Senior Director of Global Product Marketing, would also take part in the blue team.