Apples AI is mostly processed on device. That’s why it takes an iPhone 15 pro or an M-series processor. They also claim that what is processed in the cloud is neither identifiable nor stored, just processed. We will know if that’s true (at least what is being sent) as soon as it gets out into the public and we can start picking apart the traffic.
There is no mention of opt-out or not yet, probably because we’re several months away from the actual release. I’m sure we’ll get more information before then.