[Fixed formatting. (Please use preview, also {{{ }}} is for preformatted text, not quoting, so I italicized the quote from the doc instead of just fixing the {{{ }}} placement, since with the triple curly brackets you just got a long quote that you had to scroll right to read.)]
This proposal does not have enough specifics to be a viable ticket. You say you are sure Django knows the context of which app is currently running, but that is not true. When servicing a request, code from many apps may be called. When rendering a template, code from many apps may be called. The only things strongly tied to an app in Django are models, and perhaps (given how django.contrib.admin.autodiscover() operates) admin definitions.
There is no notion of a "current app" when url patterns are being evaluated, nor when a template is rendered. So it isn't at all clear to me how you expect Django to auto-determine an appropriately unique app-specific prefix for named url patterns, neither when they are evaluated/named nor when they are referenced via {% url %} tags. Without such specifics, I don't see how this ticket is going to make any progress, so for now at least I'm closing it as invalid.