I remember reading about them on UK forums when No Country came out, IIRC they certainly weren't uncommon (nor were they regarded as 'highly' effective); regardless - it isn't the 'first' - right?
Call me funny, but words have meaning and credibility is everything with a can. Many of us buy them without ever hearing them in person or compared to other options; buy them when they first come out and sometimes based on promises of performance claims, timelines, or forthcoming mounts / options; wait the better part of year for them; and are then married to them for life. The industry as whole seems rife with companies that play fast and loose. Silencerco is going through a lot changes. I guess we'll see how it all shakes out.