These are the PCs receiving the May 2021 Update TODAY

[Windows Central]

The May 2021 Update is now officially available, but not every PC is getting it (on day one).
Starting on May 18, 2021, Microsoft is finally making available the Windows 10 May 2021 Update (version 21H1). This rollout represents refresh number eleven for laptops and desktops, and it is yet another update that brings improvements for security, remote access, and overall quality.

Full story from the WindowsCentral blog...