[jjoonathan]

> The phone has no way of knowing

It could make a useful guess based on device identifiers. Or it could make a useless guess based on industry averages or some random device an engineer had on their desk one day. It clearly does one or the other, the question is which. Useful or useless?

[Eisenstein]

Occam's razor says they are not going to keep a list of all devices and their configurations including types of ear pieces and their sound pressure level output at each volume setting when they could just say if (volume > .75){ warning();} and call it a day. There is no benefit to going above and beyond in this case -- they just need to say they warned people.