In a recent, well-written piece by Rabbi Moshe Malubitzki shlita in Kedushas Tzion (page 14), he argues that the legendary “Four Holy Cities” (Jerusalem, Chevron, Tzefas, and Teveria) were first designated as such in the 16th century, and this, solely due to their being the largest Jewish settlements in the Holy Land at the time.
As Rabbi Yehuda Shurpin writes: The expression was coined in the 16th century when “these cities banded together for charitable purposes under the leadership of Rabbi Moshe Alshich, together with Rabbi Yosef Caro, Rabbi Yitzchak Luria, and Rabbi David ibn Zimra (Radbaz)”.
Well, we are not bound by Ottoman-era royal garments, charity bookkeeping, or its shopworn phrases. Certainly, Jerusalem always bears pride of place, and an Ir Miklat may be greater, as the Mishna says, etc. Kivrei Tzaddikim are wonderful (but found all throughout the land…). Any additional reasons to call, say, Chevron “holy” (in the same article by Rabbi Shurpin) must therefore be after-the-fact embellishments.
(I haven’t looked into this claim by Rabbi Malubitzki carefully, but it logically appears incontestable.)
Bottom line: wherever members of the Holy nation now dwell in Eretz Hakodesh, Baruch Hashem, we can say “עיר הקודש __ תובב”א”!