I wonder how far off the direct line you can be? I suspect that the coverage will be lenticular in shape, and may not include the immediate area around the transmitter and receiver. A double row stations may be required for full coverage. It probably does not extend very high either, so it may be practical to fly over it. The limited coverage severely limits how long you have to detect, classify, and prosecute the target. It also may not be sufficient to protect the nodes themselves.
The news in this article is that Ericcson appears to have been seriously developing a previously-known idea into a workable system for some degree of increased detection and tracking ability against some LO targets. This is different in my mind from some other ideas, like the "cell phone tower radar," because a real name in radar was actually doing it and apparently believed they could succeed. There's insufficient information to consider it a "stealth buster," but it's not a pleasant development, either. The Chinese are experimenting with various LO detection technologies, this particular concept is not new, and thus you can safely assume they also already have a development program along these lines.
The scheme does include detection potential by receivers at angles far off the lines of bearing from the transmitters. I'd say it is more than just a border fence, it is more like a web covering the interior of the defended country. However, that still depends on how much energy gets scattered in the various angles from each of the transmitters to the target and then to each receiver. As the article and WarNerd pointed out, that is often going to be primarily in close to a straight line from transmitter through the target to receiver, which would be due primarily to scattering off the bottom surfaces of the target. However, the RCS of air vehicles is a spikey thing, and each one gives stronger returns at specific geometries, especially if you're looking at it from a relatively co-planar aspect, as opposed to from higher above or below the target. A distributed web of transmitters and receivers is able to exploit these spikes better than a single radar that would only see them for brief moments, if at all. This is especially likely for very low altitude targets like cruise missiles, which is what this system was apparently meant primarily to track. High flyers, especially the F-22 at 50,000ft, would be less susceptible to detection except when it flies substantially across the lines between each transmitter and receiver.
Whenever discussing "stealth busting" ideas, people always need to keep in mind that detection and tracking are only the (necessary) first two links in the kill chain. Any IADS still has a long way to go before successfully prosecuting the engagement. Furthermore, we still have our full range of techniques to degrade their ability to do so, even including their ability to detect and track using this multistatic system.