That's interesting, I wonder if they are counting falsetto for his upper notes, or if he hits those in chest voice, or a mix. He sounds like he has had some voice lessons/coaching and he can control the placement of his notes. His breath support is fantastic. Also, I wouldn't classify him as a tenor; IMO he is a high Baritone. I have worked with a lot of singers, and Tenor vs. Baritone is more than just range, it is also a vocal tone quality.