Selig's concern is that the Yanks are parking club money over at YES. Of course they are! This is a variant of a tax dodge, driven by revenue sharing. You want to keep "your own" money out of the pool of revenue that's shared with everyone else. So you book as little revenue as possible on the club side of the company, and shift it to the media side. How? The club's payment from the media side for broadcasting rights is pegged well below market value. Having a media company is a good place to hide some cash.
If Selig goes after the Yankees, he'd better hire an army of accountants. Every team with the opportunity parks media revenue because the incentive is huge. Tricky problem.