I wonder if perhaps the noise of families ratting each other out is getting too loud. This sounds like a solution to cut through the noise and have their own data. Like you said, this does go a bit too far. It also does not seem to properly equip the school district with factually correct info. Metal on wheels isn't a good data point for "You live here".
The kind of district where people would rat each other out at any rate that would cause non-trivial amounts of work is going to be full of exactly the kind of people who wouldn't see anything wrong with treating a circuitous 3rd party ALPR enforcement system as authoritative and would have the spare $$$ to pay for such a boondoggle.