The concept is fine until you meet real world conditions. Drivers following will be watching the screen and not what it's showing or the back of the truck it's on. Others will use it to make riskier overtaking moves.
Also a lot of the time you'll be watching the back of a truck showing the back of the truck in front showing the back of the truck in front... you'll simply have no idea what it is your looking at.
Your honour - I was watching the truck in front of the truck in front of me when the truck behind that but in front of me stopped and I ran into the back of a truck that appeared out of nowhere