A Xiaomi executive recently re-raised hype for a potential 12 Ultra super-flagship phone, despite prior rumors that it would be replaced by the Mix 5 Pro in 2022. Now, the same individual has referenced another, similarly-named upcoming device, giving rise to speculation that it will be a new Ultra by a new name.
https://www.notebookcheck.net/The-Xiaomi-12-Ultra-is-dead-long-live-the-12U.594696.0.html