I didn't miss any of the nuance but I suppose you may be misunderstanding me. I'm not expecting their name to be a unique identifier. I'm expecting their whole profile to be one. Whenever that changes re-verification should happen.
@willsmith is clearly not the Will Smith that slapped Chris Rock at the Oscars. He isn't claiming to be, but he could change his profile photo and all of a sudden the world would think he was the Fresh Prince of Bel-Air. The blue checkmark adds some validity to that claim.
I think I understand, but I'm not sure how that actually helps solve the issue of regular people with famous names being mistaken for celebrities. This is a case where everything you mention was in place (and even though they could change the text and photos that didn't happen), and still many many people were confused.
Some account handles will match real names. People make assumptions on that. At the current time, no matter of locking down profiles so they don't change will solve the problem of people assuming an account name must match the famous person with the same name, because names are not only not unique, collisions are common enough that famous people share names all the time. People don't do the barest amount of verification of what they are seeing compared to what they assume, so nothing you add that they have to look at to fix that will actually fix it.
@willsmith is clearly not the Will Smith that slapped Chris Rock at the Oscars. He isn't claiming to be, but he could change his profile photo and all of a sudden the world would think he was the Fresh Prince of Bel-Air. The blue checkmark adds some validity to that claim.