If you actually read the linked article you'll see it has almost nothing to do with graphic or web design, but rather digital design is used as a less highbrow synonym for "information architecture".

I did "actually" read the linked article. I also did a Google search for "digital design" to see how it's most commonly being used. I'm comfortable lumping everything I saw into "graphic and webpage design," with the assumed understanding that "webpages" are basically applications now.