The VU meters aren’t necessarily hooked directly up to the signal - it’s reporting an averaged value and hence is a low pass filtered version of the signal - it’s intended to report an approximation of the level of a signal that’s close to what we might report when hearing the signal.
Some digital implementations don’t accurately represent what a “standard VU” meter would report. You could argue that the VU meter definition is dated and we can do better now, others argue that you shouldn’t call it a VU meter unless it matches the readings that the electromechanical device from the 30’s or 40’s would give.
The net is that a standard VU meter will be filtering out some of the ultrasonics, but especially with a digital VU meter you don’t really know what that filter is. In particular it doesn’t really tell you if a preamp or amp is filtering the signal, it’s designed to indicate how loud you’d report the signal to be (and you have a filter that doesn’t respond nearly as much to ultrasonic energy.)
What I can tell you is that from release to release of the DS software all of you like the results filtering the signal less and less and letting more ultrasonic energy thru, i.e. that you’all like to hear more harmonics of the signal, go figure - I have to balance that against the number of user’s who’s systems don’t react well with too much ultrasonic energy. Ironically some systems definitely sound better with more ultrasonic noise…