"In this world, each product stands on it's own feet. There is choice and there are no geographical markets, just fans and the content they choose."

The way that things are moving, will tend to create geographical markets for collegiate sports networks. For example, sure there will be a certain percentage of "ex-patriots" and others outside of the Pac-12 geographical footprint that want to regularly watch Pac-12 games, but the vast majority will be in a specific geographical, aka regional, market. This is to be expected because people tend to become fans of one or more teams that are "local" to them.

Methinks that you are assuming that the move from subscription-based service to the individual choice service makes everything global. Making the access global does not change the geographical distribution of fans of an particular team.

BYU and ND are probably the atypical examples, due to being religion-based institutions with a wide-spread (more so with ND) fan base. Most public universities outside of a few of the "elite" FB or BB schools and most of the other private ones cannot make that claim.

Even BYU's claim is mainly a geographical one, i.e. the inter-mountain area and parts of the west coast - not so much elsewhere.