I did some reading when I first came across this "scientific" publication.
It's definitely very narrow band. It could handle wider bands, by combining multiple units. However, each one has a depth of a few inches, which means it would become rather large.
It also only handles noise coming from a hole.
What is new, is the math behind it, allowing to automate 3D printing of noise supressors with a large opening. That opens up a lot of new applications for mufflers. Maybe we'll see it on jet engines, fi?
I still wonder why this shows up in a lot of places, while other science doesn't seem interesting.
There was a company exhibiting tranparent square building blocks for cubicles at NAMM. No details, but the marketing speak suggested it could be somehow related. Sorry, don't remember the name. Just wondering if anyone who visited NAMM spotted their presence?