According to the latest leaks, Xiaomi may defy expectations by replacing a successor for the Mi 11 Ultra with the Mix 5 Pro. However, a new Weibo post from an executive with the company suggests that this is not the case and there will be a top-end 12-series variant after all. The device might be released soon in order to honor the OEM's CEO.
https://www.notebookcheck.net/A-Xiaomi-12-Ultra-launch-in-2022-is-back-on-the-cards.593885.0.html