I would hold off on this update for a couple of days - several people have had their user files deleted because of it: betanews article, pcgamer etc. It looks like it is linked with non-onedrive backed up user documents, and as in one case a user had the contents of their non-system D:\Document drive deleted, make sure your backups include all your drives. One reddit thread recommended changing the GPO settings to disabled/not configured for:
Computer Configuration/Administrative Templates/System/User Profiles/Delete user profiles older than a specified number of days on system restart
But as the issue has also occurred on Windows 10 Home installs this may not be the correct work-around.