How would this affect Chrome on Android, which allows you to redirect localhost requests from a phone to access localhost on the computer it's tethered to?
That's done via port-forwarding. That is, Chrome is talking to the loopback interface on a particular port. The server listening at that port forwards the requests across the debugging bridge to the phone, and ferries the response back across in the same way.
It should be unaffected by the suggestion in this document.