It does have a good resemblance with your measurements so the Tenore measurements must be somewhat realistic at least.

I can't believe no one complaints about this roll-off ?

That doesn't necessarily follow.  Inductively, you make a cogent argument but it is not necessarily valid.  We won't know how sound it is until we get actual confirmation of the phone in question.

I'm skeptical myself as I do not like dark phones but I didn't run them through my suite of triangle, bell and chime test tracks.  I do find it suspect that 4khz before rolling off another 15-20dB is enough for pretty much 98% of all the impressions to not feel they were missing any significant treble.  If that's the case, it just means there's an abundance of information up there that most people don't mind missing out on.

I did note the following in my own review though:

http://www.changstar.com/index.php/topic,1643.0.html

"I like the smooth and natural lower to mid treble on these.  If only they could get a bit more sibilance from the crashes."

"Timbre is much closer to the UERM than the ER4 which is a good thing.  This is good enough in my mind to help compensate with any resolution deficiency to a relative non-issue versus the ER4."

We also agreed the treble seemed too smooth in a colored and forgiving fashion.

"I’d say there is tonal trade-off here between the bite of the UERM and smoothness of the Zeros."

Then there was this.

"This confirmed my suspicion that while the mids and vocals of the Zeros are pleasing, they are ever so slightly recessed and a bit unresolved at the highest level, though they are smooth and not dry or crispy as is one of my pet peeves with some IEMs and phones that can’t do vocals.  By comparison, the UERMs just pull out so much more information on vocals like lips and deep breaths, stuff down in the throats and lays it out in a very smooth, natural, resolving and textured presentation."

So roll off was expected, but not 15-20dB worth in my mind.