WiiM was broadcasting AirPlay at one point in the Pro/Pro+, but that is not the issue here. The issue here is Ultra to act as a AirPlay receiver (and yes that should sell iPhones).I think the underlying issue is money. Apple wants everyone to be able to receive Airplay, because it sells iPhones.
Broadcasting Airplay is trickier. That competes with iOS and MacOS devices. So money needs to change hands.
ID chips are tricky. See Windows 11. Apple does the same thing. Apple won’t upgrade MacOS on older Macs, and banks won’t trust older Macs. The ID chips need to be surface mounted, or more ideally, imbedded in the CPU.