They can simply make sure your iBeacon proximity uuid doesn't get registered with the OS if you aren't a certified vendor.
No uuid registration with the OS and people using your app will not get a background notification for your iBeacons.
This would leave app developers with only having the ability to detect beacons when their app is foreground, or during background processing time.
Note: There are no checks like this today. You can advertise any UUID you want, and have your app subscribe for notifications if the os detects the iBeacon in the background.