I kind of feel like the article reflects an incomplete understanding of high intensity interval training. HIIT is a form of interval training, not a form of high intensity training. It has intervals of lower intensity, and some forms of HIIT never get into the anaerobic range. Even the "high intensity" parts are only high intensity relative to most cardio training.
And frankly, the regimen he suggests - training at 150 bpm heart rate - is actually pretty high intensity as well, as aerobic training goes. I'm certainly willing to believe that doing it for 30 minutes a day instead of 10 minutes a day will result in marginally greater aerobic gains - if you have the time to do that.
I do think the point he brings up about heart stroke volume is interesting. That may be difficult to develop without longer periods of aerobic training. But again, you have to have the time for it.