@kuribo From the website -
The Class D amp has the same kind of distortion signature {as tube amps}, but at a much lower level.
This, to me, is reasonably unambiguous. From what I understand of Hypex and Purifi (and others, of course) amplifiers, they make no such claim about harmonics. I suspect measurements may confirm this. I’d bet on it.
I’m as concerned about the definition of the market as you are with your amplifier preference. "in the market" would be the worldwide production and sale and availability of stereo amplifiers. Within this there are many other more narrowly defined markets like an overlapping mess of circles on a page, each with their own and overlapping characteristics.
So the "great number of people" must be taken in this context.