You can’t decouple Siri from the OS. It needs deep access in to sensitive areas of the OS. Decoupling it would just result in mass abuse of user data far beyond the problems of music links.
Siri is OS and fine to be in the OS. The vendor of that OS should not also have services like selling music brokered by preferential treatment by the OS.
> To avoid running the main processor all day just to listen for the trigger phrase, the iPhone’s Always On Processor (AOP) (a small, low-power auxiliary processor, that is, the embedded Motion Coprocessor) has access to the microphone signal (on 6S and later). We use a small proportion of the AOP’s limited processing power to run a detector with a small version of the acoustic model (DNN). When the score exceeds a threshold the motion coprocessor wakes up the main processor, which analyzes the signal using a larger DNN.
Yes, as with all things they could come up with a way to let third-party apps program the AOP with a different detector, but my point is that Siri has deeper integration into the device.
Apple's privacy and security rules also limit what a third-party app could do. For example, Siri knows what apps you have installed, but apps aren't able to access this information. Siri can make modifications to system settings; apps cannot.
