I figured from the title I'd get a better explanation in the comments, and I was right, but I think the article is not nearly as bad as the clickbaity title suggests. It's a decent introduction to how to use types to simplify code, and the basic idea that your types should reflect what you know about the data is extremely powerful. If you go to the trouble of checking that your data meets some constraints, you should be able to represent it with a more constrained type afterwards, and that is the essence of parsing. It all makes sense! Even the title makes sense, as a quick way to reference and remember the idea after you've learned it.

But, yeah, the clickbait title put me off, and you're right that the terminology is unhelpful, since the distinction between parsing and validation isn't consistently made, especially in practical work. Virtually all of the "validation" code I've seen in statically typed languages, in the codebases I've worked in, would be "parsing" by this definition.