Maybe following was a typo to include iphone in support?
Not seeing the similar (beta) USB driver support option in ARC for iOS (16).
My understanding is that ARC has always been bit perfect with iOS when using an external DAC. So this news is about the addition of that for Android.
iOS works differently to Android with attached devices and has always passed through as bit perfect, where Android by its design resampled everything unless you coded your app or version of Android (DAPs) to bypass the system mixer and pas on but perfect. Roon found they produced better results if they performed the resampling so that was built in to all Android apps. They changed this for ARC so it can pass through bit perfect to an attached DAC.