A small update to iOS 12.1 for the iPhone XR has been released by Apple and it appears that it is only for those who haven’t updated to the latest version of iOS just yet. The new build is 16B94 while the original iOS 12.1 build was 16B93.
If you have an iPhone XR and have updated to 12.1 already, you won’t see this update. Rather, for those of you who buy a new XR, which will come with iOS 12.0, or those who haven’t upgraded yet, you will get this new 16B94 build on your iPhone.
It is a bit of a mystery as to what this update includes as there are no release notes. It is likely that it is simply a bug fix update for something that was only impacting the XR. The original iOS 12.1 update for the iPhone XR included a wealth of updates and brought several new features including eSIM support, Group FaceTime, and 70 new emoji. Content wise, this new update appears to be exactly the same as the original. This is what leads me and many others to think it is simply a bug fix – but what it fixes exactly is unclear. It is unlikely that Apple will issue any release notes on it so we can all remain in the dark together on it.
This is not the first time that Apple has released a special one-off build for an iPhone or an iPad, although it is rare. Generally speaking, most of the time when they do release one, it is for a particular region for devices and not specifically for one device.
If you have an iPhone XR and have not updated to iOS 12.1, you can do so by going to Settings>General>Software Update. Given the size of the update, it is recommended to one download it when you are connected to WiFi.