Thank you!
I have a Dell XPS13B laptop with an i5-7Y54 processor, and have always been told that any 7th generation Intel CPU meets the requirements for Windows 11. Now, however, the PC Health tool notes that my processor is not supported for Windows 11, even though I had done a fresh install of Windows 11 on it a couple of years ago without issue. Installing KB5027397 has, indeed, made Windows Update install 23H2.
Only concern now is that if I need to re-install Windows 11 on this laptop I won't be able to, as I'm pretty certain the media creation tool will as a minimum build 24H2 into it, and then complain that my processor is not compatible. Not very nice that originally this processor WAS supported by Windows 11, but no longer. Don't move the goalposts after the game has started, please.