TV stations are not always forthcoming to cable system operators long enough in advance for the cable system to make decisions on carrying sub-channels. I've known a few CATV tech people over the years (heck, back in the 80's I used to pass on viewer complaints to one because they had RFI over channel 6 from the station I worked for), and you would not believe the stories, most of which I actually can't repeat here. It could have been that no one thought they had to contact Comcast or maybe they were too busy getting the thing up and running and it slipped their mind or whatever. I'm guessing the slipped their mind due to busy reason as I just noticed legal ID's are now being displayed on this channel for the first time today since they opened up the .2