The RAAT support on iOS acts like any other RAAT endpoint–it is discovered by the core via multicast or broadcast packets on the LAN, and then the core initiates connections to the endpoint.
Squeezebox endpoints work in the opposite direction–endpoints discover the server and make connections inwards. This is easier to bridge over the internet, but creates significant architectural/UX compromises elsewhere.
No we will not re-architect RAAT to make it more like Squeezebox. There are good reasons why we did it this way. When we do broader work on “the mobile problem”, we will address the remote streaming use case holistically.