I took his comment in the video to mean he was showing how some sloppy harpists might play, exaggerating it for emphasis. It reminded me of some amateur videos of players with poor technique. I didn’t take it as a did at non-Salzedo technique but rather a demonstration of generally sloppy technique.
Regardless, I think these are overall a good thing and I’d welcome videos by harp teachers showing either basics like tuning and string changing or playing technique. Even someone with a good teacher would enjoy something like a video of trill techniques they can pause and replay at home, with close-ups and angles that demonstrate it clearly, maybe even using slow motion.