Can anyone tell me why this game was not televised last night?
I watched it in Richmond on CSN (576). Where are you? If you are in Hampton Roads, it might have been beyond the reach of that NFL broadcast region. Richmond is outside the reach of the broadcast area for Baltimore. Local stations can buy the game and show it, but regional networks are restricted within their footprints.
Pre-season games are also subject to the same blackout rules as regular season games. Here in Tampa, we have been dealing with that for the past three seasons. Hopefully, you have better stadium attendance than we do.