Huh?

You just said it “isn't reliably updated, and so pings on vehicles that were reported stolen…” are weeks out of date?

Even if all ALPRs vanished from the Earth tomorrow, that still indicates a lack of credibility in the pings?

If I had to guess, it's like when an expensive medical test gets more accessible and they have to update their model.

If the cost to get an MRI means everyone that gets one has a combination of symptoms and risk factors raising the pre-test probability, then it makes sense to treat MRI findings aggressively. If they become cheaper and start using them as screenings, they need to update their approach.

Similarly, if license plates are scanned when cops are already pulling someone over for moving violations (or the car is accumulating a ton of parking tickets, having been dumped), it might be ok if their status isn't updated that frequently, and it still might make sense for cops to approach the car with the idea that it might be stolen (something a drivers license check against registration can quickly clear up, which shouldn't matter too much if they were getting pulled over anyway).

If the system is being used to justify pulling people over in the first place, it needs different parameters.