iPhones already have this feature if you hold your phone up to your ear. There is a microphone in the back of the phone near the camera that phase cancels out background noise from the input from the front mic.
They need this for the AirPods then. Everyone I call while outside in NYC says the microphone is super sensitive and picks up all the surrounding noise.
they also recently added 4 (or 5?) mics on the new iPad Pro so that it could do facetime calls while cancelling out the feedback.
Wouldn’t be surprised if a software update makes it possible to use all of those mics for some very good ambient noise cancellation during face time calls
