Apple's iOS App Store review process now includes a requirement that apps should work on IPv6 only networks.
With that in mind, is Apple defaulting to IPv6-only, on an app-by-app basis, for iPhones connected over mobile networks in the real world (not just in review)?
I.e. is Apple now forcing the move to IPv6-only in the real world for apps that pass it's IPv6 review?
(Any answer to the above question(s) would be great by itself, but for those with in-depth knowledge, a follow-up: Would UDP packets be properly routed to/from an IPv6 mobile device to an IPv4 server via NAT64 on the cellular network? It's actually this concern that leads me to the original question, I'm wondering if TURN clients are using TCP instead of UDP because UDP is not making it through IPv6->NAT64->IPv4).