I did dig a little
I found this wiki on exciters
“An exciter (also called a harmonic exciter or aural exciter) is an audio signal processing technique used to enhance a signal by dynamic equalization, phase manipulation, harmonic synthesis of (usually) high frequency signals, and through the addition of subtle harmonic distortion.”
It seems they do work as described by the article.
No, the article is not an accurate description at all, since it leaves out everything on that list except "subtle harmonic distortion" - which wasn't 2nd.
I would not use a wiki source as gospel in any event. Reading Donn's patents is far more enlightening.