Apple is expected to release iOS 18.4 in early April, and when it does, users with HomeKit devices still running on the old Home app architecture may be forced to upgrade them to the latest software.
Apple has offered users the option to upgrade to new Home architecture since March 2023 when it released iOS 16.4, iPadOS 16.4, and macOS Ventura 13.3. At the time, Apple said the new architecture brings faster, more reliable performance, especially for smart homes with a lot of smart accessories installed.
However, not all users were entirely convinced of its stability, mainly because it was actually the return of the update's availability after Apple temporarily pulled it in December 2022. Apple's decision came after reports of HomeKit devices becoming stuck in an "updating" or "configuring" status, devices going missing entirely, invitations to share the Home with other users failing, HomeKit Secure Video recording not working, and more.
Apart from the above issues, many users opted not to install the update because the new architecture breaks support for the Home app on devices running older versions of iOS, iPadOS, and macOS. However, code in iOS 18.4 beta 3 unearthed by MacRumors contributor Aaron Perris suggests Apple is going to end support for the original HomeKit architecture. Code strings include the warning "Support for your current version of Apple Home will end soon. Update now to avoid interruptions with your accessories and automations."
It's not clear if the policy will immediately come into effect when iOS 18.4 is officially released next month, but the existence of the code strings is telling, suggesting that iOS 19 almost certainly won't support the old HomeKit architecture when it arrives in September.
