You can control what songs can be decoded with what adapter.
You can control the bit rate and quality.
You can effectively make songs that only play on certain headphones or songs that play better quality when you have your beats plugged in.
This isn't the first time this has been brought up this was the first thing everyone had in mind when the rumors about Apple ditching the headphone jack first appeared.
Not really, they can't tell what headphones are plugged in they might be able to determine some very coarse profile but even that is highly questionable.
With audio being pushed through lighting port in a digital format Apple knows for sure what device is connected to it, and even if you spoof the device id they can still use DRM because the device decodes the digital signal and if it doesn't have the correct set of keys or decoding configuration it would not be able to play the audio.
You can effectively make songs that only play on certain headphones or songs that play better quality when you have your beats plugged in.
This isn't the first time this has been brought up this was the first thing everyone had in mind when the rumors about Apple ditching the headphone jack first appeared.