Apple's upcoming iOS 18.4 software update will require users to update their smart home and installed accessories to a new architecture for the Home app.
Strings in the iOS 18.4 code suggest that support for the old Home architecture has been removed, indicating Apple will force the new architecture on all users.
The new Home architecture will be required to continue using HomeKit devices, despite past complaints about problems with the new architecture.
The new architecture is claimed to be more reliable and efficient, especially for homes with many smart home devices.