Usually when that happens, it's because a big company is interested in the tech and want to purchase and patent the idea. More than likely the big company asked the inventor to remove all traces of the idea/product off the net to limit exposure.there was a reef pi that was supposed to bring that to the market but they vanished scurbbed the net of all traces, YT vids, website, FB, etc.
Keep an eye out for it to hit the market in a few years and you'll be able to put the pieces together and deduce what happened.