Daniel Desjarlais (Xiaomi Communications Director): Xiaomi 13T and Xiaomi 13T Pro will include 4 generations of Android OS upgrades, as well as 5 years of security patches.
It's really good to see this spreading to more manufacturers (although I'm not sure if this will also apply to their lower range devices). Especially because even though your OS updates may be capped at 4 years, you will still receive app updates for 2+ more years, including system apps. As opposed to iOS, where your system apps stop at your last update and developers bump minimum OS versions quite quickly.