That... seems an awful lot like that bit where Uriel is talking about exercizing free will: all mortals can do it, but most don't.

I think that Harry is exceptional not because he can Name things/people, but because he does name them.

Then again, if we're talking about outsiders, all bets are off.  Naming them is totally one way that the whole starborn ball of noodles can manifest.

Perhaps it's related to the idea behind Mantles/Masks. Give something a new name along with new expectations as to the personality behind it, and by using that name the being expresses some of those traits.

Concerning Uriel, he doesn't really directly interact with many humans. Perhaps that could directly give Harry more influence over him with regard to naming. Alternatively, Harry could have more influence indirectly by spreading the use of the new name after their meeting which given Harry's influence could result in the new name being used by many people.