There's an upside to this, yes ingress will still be blocked by default (good!) but with uPnP or something along those lines, we now open a single port and it's a 1:1 connection. No longer are we limited to having one device in the household holding that forwarded port and all traffic hitting the external IP going to a single internal machine.

This would allow two users to have the same port opened. This makes it easier to communicate with others on the internet.