Apple patches ancient iOS versions to keep iMessage, FaceTime, other services working

When Apple stops supporting older iPhones and iPads with the latest version of iOS or iPadOS, it usually isn’t the end of the line—Apple keeps releasing new security-only patches for those devices for another year or two, keeping them usable while their hardware is still reasonably capable.

Apple updates iOS 12 to extend iMessage and FaceTime support on older devices

Apple has released iOS 12.5.8 for a small group of older devices, to make sure they can continue using FaceTime and iMessage.

Apple revives iOS 12 with critical update to keep iMessage and FaceTime alive on older devices

Apple has released iOS 12.5.8 and iPadOS 12.5.8 for a limited set of older devices, extending the security certificate required for iMessage, FaceTime, and device activation beyond027.
Macworld

Apple updates iOS 12 for the first time since 2023

The update demonstrates Apple’s continued support for legacy devices, ensuring essential communication services remain functional on older hardware through 2027.

AirTag refresh prompts mass updates of older iOS, iPadOS versions

The introduction of a new AirTag has led Apple to issue updates for multiple older versions of iOS and iPadOS, all to maximize support for the tracking device.

These 'Obsolete' iPhones Just Received a New Update

Apple released a new update for the iPhone 5S, iPhone 6, and iPhone 6 Plus, but don't expect any new features.