I recognized the same thing in my unsupported system's 22H2 to 23H2 migration. Glad to hear 25H2 will be a similar deal especially since we won't need a huge platform shift to get those bigger features user-facing features. Hopefully it'll be like that time when we got relatively big changes...
To hopefully get the thread back on track, I've done some research and it looks like OP is not alone. There have actually been several people (Reddit, answers.microsoft.com, DPReview, Borncity) experiencing issues with 24H2 deactivating their Windows installation as you can see below.
Windows...
Not really, just because the build number hasn't been updated doesn't mean the code itself hasn't been changed. The lack of updates to the build number is just in case an older program has a habit of checking the kernel version number.
I actually like this workaround alot better than bypassNRO. The command is much easier for me to remember, and I don't have to worry about mixing backslashes and forward slashes.