Where? I can't see it. Even a fractured Chicago market is worth more than a full market of any of the cities left. Even if you give the Sox a 1/3 share of the 10 millionish population of the metro area as "fans", there isn't a single metro area in the US which doesn't have a team already. The only one in Canada is Montreal, and we know what happened there.
You don't come to an American city until you get down to Charlotte at 2.5 million