HBO is star driven. It's true of its original movies. And it's true of boxing. In other words, boxing is basically an ongoing series on HBO, like Sex and the City or The Sopranos. And like any series, it requires familiar faces and interesting foes to build a viewer base.
Viewers follow their favorite fighters and wait for the next episode.
These are the fighters it has signed to longterm contracts. That means the bottom two tiers in HBO's boxing programming have to feed the top two tiers in a direct and purposeful way. Taking HBO's four boxing programs one at a time, it makes sense to start with KO Nation. The role formerly played by Ed Lover has been eliminated, and HBO is currently auditioning announcers for fighter introductions. Fran Charles and Kevin Kelley are still in place.