Not sure if any of you ever did this, but from time to time I make a basic PE from a Windows 10 Insider Preview, just to see if anything has changed with PE, or if Microsoft has screwed up something (there have been several cases of that).
I basically just export image 2 of a UUP esd file (for example: Professional.esd), do some minor servicing, and boot it.
(image 2= "boot.wim", image 3="install.wim")
The special thing about these PEs was that they always expired after a while, so if I set my PC date a year ahead, the PE would refuse to boot and immediately told me the files had expired.
The nice side effect to this was: When I suspected an Insider Preview to be an "RTM" version, all I had to do was make a PE from it, then do the "expiry" test. If it did NOT explire, the Insider Preview was RTM.
I wanted to prepare for the new Windows 10 1803 version (probably out next week for insiders), so I did a quick PE test on preview 17123, and to my surprise this PE does NOT seem to expire. Of course, I know this is NOT the RTM (it still has the desktop watermark), but it seems to me Microsoft has abandonded this "Expire" thing completely. More tests (17110, 17120) seem to confirm this.
Has anyone heard anything about this? I always found this PE expiry thing was weird to begin with, and maybe somebody "turned it off by accident" over at Microsoft, but I really wonder if there is something behind this decision.