Yea same, Im surprised it's the first time I'm hearing about this as well. Maybe it's due to the fact that it's a Japanese study and the North American SLPs haven't caught on yet? In the video he mentions another study that tested something similar but in that study they used also real-world practice. I think that one was by an English or North American researcher. I also found other videos on YouTube from SLPs using this. As well as something called interactive metronome training. Also the research paper mentioned that this kind of therapy is also used to treat Parkinson's patients who developed a stutter.