That is not a page of the Manual of Style. I asked immediately after the date-delinking  decision whether it covered the Naming Conventions (now Article Titles, and was told that it doesn't - I have been editing them for the year.
My impatience was because there has been a steady stream of questions why American municipalities differ from others, and a clear answer, which we have had to repeat  every time the talk paqe was refreshed.  The reasons for the present wording are clear, but long buried in the archives; the purpose of guidelines is so we don't have to repeat ourselves. Time to put it in the guideline.  PMAnderson