A lot of cable providers are dropping the listings grid from the TV Guide Network feed, Cox Communications here in Oklahoma City dropped it when it transitioned the channel to digital cable only, and relocated it to channel 70 from channel 2 (whose channel slot now houses WGN America) last year. It moved the TV Guide Network grid to channel 3 (which carries sports programming, along with various other locally-produced programs) but limited the grid only to subscribers with analog cable. If memory serves me right, virtually all Comcast systems are digital-only now, so there probably isn't a need for Comcast to relocate the grid to one of its local origination channels.
Now that the FCC has put a time limit on the discontinuance of analog cable transmissions, set to take place by the end of this year, it is likely the TV Guide Network program grid will fade into history, since people can access TV listings online, through on-screen guides programmed into their digital cable converters and through mobile apps.