There are different kinds of high end. As that video shows, along with Leon Todd's video, and every other clip I've heard, and when I've played the amp personally, I hear an amp that does produce a lot of upper harmonics, yeah, but they're harmonics that come from the clipping of mids and lower-mid frequencies. I don't hear much detail or articulation from the guitar at all, because the amp seems to filter a lot of those frequencies away before the preamp gain stages.
You can take any guitar with a tone knob and turn that knob way down, and still get a ton of fizzy upper harmonics from most high gain amps if you turn the gain and presence high enough, but it won't be detailed or articulate information, it will just be fizz that's coming from what happens when you distort lower frequencies hard enough. That's kind of what the VH4 sounds like to me.