Otherwise there will be problems with the backups.
September 18, Apple released the first beta of iOS 12.1, which returned the group calls on FaceTime. Updating in any case you cannot install those planning to buy iPhone XS or XS iPhone Max. For updates on the beta version, these users will be without the ability to recover their data to a new iPhone.
What’s the problem?
In the list of iOS 12.1 beta 1 no iPhone XS iPhone XS Max. This means that at the moment Apple has prepared iOS 12.1 for new smartphones. If you install iOS 12.1 beta 1 on your smartphone and make a backup, then after purchasing the iPhone XS iPhone XS or Max will not be able to restore the mobile from the backup.
To do this will fail because the iPhone XS iPhone XS Max is installed the final version of iOS 12. The ability to install the beta of iOS 12.1 on the screen temporarily is not expected.
A similar situation in the past year faced many buyers iPhone X. They tested iOS 11.2 on their smartphones, waiting for when it comes to pre-ordered iPhone X. When the smartphone was from their rightful owners, they simply couldn’t restore the device backup from the wrong system. As a result, for several days people had to use smartphones that have been configured from scratch.