Well, I've skimmed through your link and he makes some legit counterpoints. The teenager different sleep schedule is not addressed by the link so maybe true at some degree, but still, when there are so many errors one became skeptical. (This assuming this errors are true and they disprove many of Matthew Walker points, I have not looked at the article deeply as I said)

I am going to read it more carefully when I have more time.

(Jeez, it's really hard to believe something nowdays)