The link you attach is from 2008.

I have bad feelings about Tom Yost. He loved the outdoor life, and his technique for building folding/inflatable boats very cheaply is brilliant. The fact that he decided to share it with the world instead of monetizing proves he's a extraordinarily nice guy.
I don't believe he simply decided to "neglect" the Yostwerks website. Based on a few of his pictures, he's an elderly gentlemen. I seriously doubt he would've gone for so long without single word on purpose.
I wonder if there is a way to check on his well-being?