I wouldn't say this is a bug, as it was purposedly added to the game. I guess the idea is similar to what happens with the music.
I don't know how to prove this, but here an extract from the tuning descriptions Maxis makes available after each patch:
"distortion_speed - Game speed at or above the distortion speed will have a distortion effect applied to the video when that speed is selected."
TVs have set that their distortion_speed is speed2. This means that for the video on TVs, speed 2, speed 3 and ultra speed will be distorted.
This was there on 1.14, but not on 1.13.
Additionally, now TVs also mute when on speed 2 or above.
