If you have a new iPhone XS or iPhone XS Max scheduled for delivery on Friday, do NOT install the new iOS 12.1 beta on your current device.
As pointed out by Cult of Mac, any device backups you make after updating to the iOS 12.1 beta will likely not be able to be restored to your shiny new iPhone XS or XS Max, as it will be running iOS 12.
Apple released the first beta of iOS 12.1 to developers on Tuesday, just one short day after the official release of iOS 12 to the general public. The iOS 12.1 beta, which contains the ever popular “bug fixes and improvements,” also includes the ability to make group FaceTime calls, a feature that had been pulled from iOS 12 during its beta testing period.
Apple has not yet made an iOS 12.1 beta available for the iPhone XS or iPhone XS Max, making it impossible to restore an iOS 12.1 backup to either device, which should be running iOS 12 out of the box.
iPhone X buyers faced the same dilemma last year. While it should be noted that Apple did roll out an iPhone X-compatible on the day the new device hit shelves, but iPhone X users had to wait for a number of hours before they had the ability to restore their data to their new handsets.
If you were running the iOS 12 beta, be sure to turn off automatic updates in the Software Update menu to prevent the iOS 12.1 beta from installing automatically.
Beta users can also remove the iOS 12 Beta Software Profile from their devices by entering the Settings app, tapping “General” -> “Profiles & Device Management.” Next, tap the iOS 12 Beta Software Profile and then tap the “Remove Profile” button. You’ll no longer receive beta updates on that device.