I thought the intent was to give MLB Network a place to run their game drop in coverage on nights when a full game was scheduled on the main network channel? Once the full game is over the drop in coverage can return to the main feed.
True, baseball is a different game. The only minus I have (so far) is they sign-off before ALL the games scheduled for the day are over; NFLRZ does not do that.
It would be nice if it continued, just so one would not have to switch channels. Or perhaps simulcast 152 on 153 until the allotted time expired.