Earlier quoted context omitted.
There is no way to control the iOS firewall via extensions in iOS. Meaning, it's still not supported, and what you see as "essentially" the same misses the point. I want to block connections of specific apps. What iOS can do is reveal connections made by the network device to the outside. Duh. Set up Wireshark on some AP and get the same info.
Niche startup idea, VPN for your mobile device that can analyze and block traffic. Block entire countries, 3rd parties, etc. Give realtime feedback on their dashboard as applications are loaded. Could also be useful as a developer application profiling tool.
Facebook attempted such a thing already, and was caught exploiting it. VPN apps for the purpose of traffic control and monitoring are dangerous as they rely on some other party. I could do the same thing without ever needing a service for that. Setting up a monitored VPN gateway is no rocket science for me, I could do that, but the folks using crappy apps couldn't. And I would still need a way to map traffic to specific apps to identify unnecessary/malicious traffic. There is no other way as only via the internal iOS firewall. I wonder how the team behind that report managed to do that what they claim they did.