from what I've been told like for some old cartoons there may have been 3rd party content in those games the station doesn't want to air to avoid paying out. If you have kids, you see the show Muppet Babies redid on Nickelodeon (I think). The original one that came on Saturdays had Star Wars footage and other old movies they would run and that's the reason it wont air cause you got to get a license or something like that.
In BET's case, they would own the rights but do they even have the footage or with the CBS acquisition did they sell it to them? They've never came out and even answered that question.
Looking at all the free time now, ESPN doesn't even unload their full library for whatever reason as they had exclusive deals with MEAC and SWAC back in 1994 when ESPN2 launched and 2005 when ESPNU came on.