It’s probably a case of finally having a complete chain from detection to action for smaller non-aircraft crossings. There have already been government cameras in place along the smuggling routes, and you can even watch some amateur hidden footage on YouTube, for example https://youtu.be/dj_4SH_LRSI . There’s also those odd observation airships (TARS aerostats) along the border. The smugglers know they’re being observed, they just counted on low enforcement on ground crossings.

With this system it sounds like law enforcement has the ability and motivation to immediately respond to detection, something that wasn’t there until recently. It also means that as much as the smugglers can try to defeat it, a motivated and well-equipped government has the potential to stay a step ahead (see Israel for an example of this). If this tech works as advertised it might make a pretty big dent, but that’s a pretty big “if”.