I think the article is correct. Pratchett shines in his narration and commentary. The dialogue was never too pithy or impactful on its own. Quoth The Raven is an example, great name, great narration, the dialogue was okay.

To the point about the footnotes and bolding of certain characters and words, it works pretty well in the audiobooks. Still carries the same impact, they just use great narration to make it happen.

Going off topic a little bit, I think if you're creating a movie or a show, and you hire these great actors, you want to use them. You want to get your money's worth from the screen time. You don't want to have a narrator doing most of it not focusing on your very expensive actors. I think that might be the tendency, so Pratchett gets lost in translation