Comment by Vinnl
I'm not intimately familiar with the spec, so don't take my word as gospel, but as I understand it, current implementations already do name discovery. It's just that every implementation hardcodes the server name. IIRC some people have applied some kludge where they put a .well-known document on their own server to point to their instance's account, but it's still pretty spotty without that server being actively aware of that identifier. But (again, if I'm understanding correctly) servers could be updated/written to support that properly.
Not to split hairs, but that sounds more like plain hackery rather than proper extension. Let alone a viable future. I don't doubt what you say that it's possible in the most technical sense of possibility. But actually possible, in this world where we live? No, doesn't seem like it.