Cities sometimes have clear legal boundaries that feel irrelevant to the question, like the City of London, but more generally have metro areas that sprawl well into an ambiguously defined countryside. There's rarely a "this block is city, the next block over is clearly not" situation, so the number of people you include ends up being pretty arbitrary.
When ranking by population it often makes most sense to use the population of the metropolitan area. That is, to ignore the administrative divisions, which vary too much, and focus on the physical reality of the urban area.
Two cities in one City; it shouldn't be allowed.
My guess is that Apple would find it difficult to provide robust references to John to explain why it happened, or how they've fixed it for him (and whether that fix is a one-off workaround for his complaint, etc..)
Remote, proprietary personal assistants tend to apply their own (generally unknowable and unaccountable, from the user's perspective) interpretation of the context.