Apple will let you remove the security patches installed by iOS 16’s Rapid Security Response system, which can install patches without the need to fully update your iPhone (or even without having to restart it, in some cases). According to a support document spotted by MacRumors, you can remove a Rapid Security Response update by going to Settings> General> About, then tapping on the iOS Version. From there, you’ll be presented with a “Remove Security Update” button.
The document doesn’t give any examples of why you’d need to uninstall one of the patches, leaving your phone open to the vulnerability it protects against. It’s easy to imagine a few special circumstances where the feature could be useful, perhaps if one messes up some special work-related software or management tools, for instance. Otherwise, it’s one of those features that most people should probably never use unless they have a very specific reason and fully understand what they’re doing – kind of like the new extreme Lockdown Modewhich is included to protect users from “highly sophisticated” targeted cyberattacks.
Rapid Security Response is turned on by default, although you can turn off the updates by going to Settings> General> Software Update> Automatic Updates and toggling “Security Responses and System Files.” If you do so, you’ll have to wait for full iOS updates to get the security patches. Again, I’d personally recommend against turning the feature off unless you have an explicit reason to, given how many of Apple’s recent updates have patched out pretty serious vulnerabilities.
The system is also coming to macOS in Ventura, which hasn’t been officially released yet – so far, Apple’s support documents for its desktop OS don’t mention whether you’ll be able to roll back those updates as well.