The New Yorker mayor also doesn't sound right, although that's the correct demonym according to Wikipedia.
Would it be possible that perhaps the demonym is the name of the people, a noun, while the adjective is another thing, that can happen to coincide with either the place name or the demonym or something else, on a case by case basis?
Would it be possible that perhaps the demonym is the name of the people, a noun, while the adjective is another thing, that can happen to coincide with either the place name or the demonym or something else, on a case by case basis?