I'm not speaking of what would even be good for the team (although throwing away 100+ years of their culture and branding would not be good for the Sox). But regardless, it'd be worse for the Cubs (and Brewers) and you don't piss off that cash cow if you're the league. The Sox have to stay will they are, move further south to the burbs, or move out of state (this one unlikely too with TV deals driving revenue). The Northside is the absolute last thing that would happen.