why not all users receive the same Apple and iWatch OS upgrade notifications
New iOS version notification
Hi there,
You might have better luck asking this question over in Apple Support Communities run by Apple Support.
Apple stagger notification of releases so that they can a) handle the server load, and b) if any issues are found by those who first updated, Apple can pull the release so it doesn't affect anyone else.
You are free to manually check for updates and request the update whenever you like.