We should not lose sight of the fact that the Jets-Giants game was pre-season, while baseball is still well inside the regular season.
And regular season games should take precedence.
This is just an educated guess, but when WBBR, or WNYM, airs a spillover game those stations just get paid a flat fee for taking the full feed from the station that has the "rights" and putting it on the air. Those stations have no rights themselves, and essentially become a block time relay station for the games. Remember, WBBR and WNYM don't even pay to get Arbitron ratings.
As has been stated, if CBS can put the broadcast on a station it owns, and avoid paying the fee to WBBR or WNYM, for a highly rated weekend football game, it should. Constantly bouncing regular programming off the air for the many basketball and hockey conflicts on weeknights during those long seasons is a different story. Football conflicts are far more rare, and happen most on Sundays early in the season.
By promoting the fact that some games are going HD, you are forcing the hand of the listener. If they are desperate enough, then they will make the change.
The fact is that most fans are not desperate enough to be forced to buy another radio. Most fans watch the games on TV, radio is just a service for those fans who, for some reason, don't have the option to watch. HD radio hasn't even got the smallest fraction of market penetration needed before it could exclusively carry a major sports team's games. Sponsors won't pay for their ads to be carried on stations only a small fraction of potential listeners have radios to receive. Carrying major games only on HD would just be a huge missed opportunity to attract the biggest audience possible.
I know areas 15-miles from the Empire State Building where HD radio cannot be received, and that problem gets worse the farther from the transmitter you get. I like the idea of HD radio, but, for several technical and marketing reasons, it really isn't ready for the big leagues, and won't be for a very long time.