Microsoft isn't just reserving watermarks for unactivated or bootlegged Windows copies. The most recent Windows 11 Release Preview build (22000.588) applies a watermark to the desktop if you use a workaround to run the operating system on unsupported hardware. If you try it, you will see a notice asking you to visit settings to learn more. There are no feature limitations.
The company started testing the watermark on rough Windows 11 builds. The release preview shows that Microsoft is ready to issue an alert for a completed software update.
Windows 11 requires either an 8th-generation Intel Core CPU or anAMD chip based on a Zen+ or Zen 2 architecture. Many believe that the cutoff is arbitrary, and have used a Microsoft-sanctioned registry tweak to install the OS without a rejection message. The software should still work even if Microsoft doesn't provide updates.
It is a reminder that Microsoft will not help you if the software on your machine is not up to date. The watermark can be removed if you are comfortable skipping the CPU check. If you have been running Windows 11 on an out-of-spec PC without hassles, this might be annoying.