Umm . . . I'm not sure I'd accept this claim at face value. More along the lines of, "D&D can possibly handle playstyles other than gamist dungeoncrawling if enough of the subsystems are revamped, and the GM is willing to train himself/herself in highly specific techniques and principles, but the result is still, by and large, going to look and feel like 'classic' or 'traditional' D&D as you know it."
The fact that people use D&D for more things than gamist, wargame-like dungeoncrawling is more a testament to the culture of GM-ing that grew up alongside it than the game itself.
Though anecdotal, my own personal experience bears this out. As I've mentioned in other threads, "Classic" and "Traditional" D&D GM-ing were the only GM-ing cultures to which I was ever exposed between 1985 and 2012, had little real conception of the alternatives until 2017, and didn't fully understand or "grok" Story Now as a playstyle until 2021.