The choir I sing with currently pays a "professional" company to record our concerts.* The board members who deal with this company sent me the mp3 rough test files and also the final revisions for my feedback. Something that caught my eye was a steep 16 kHz lowpass filter on all of the tracks. I've never seen this before, and I'm wondering why it's there. See the screenshot below which shows it's not a shelf or bell, as I would expect for mastering EQ. This is also on past concerts, so clearly it's intentional. The only mentions of this I could find online was that it could sometimes be used for vinyl masters to avoid treble distortion when the master tape was really hot in level. That doesn't apply here. Any ideas?
*While they command a professional fee, their technique and results don't measure up at all. I may be soon taking over as the audio archivist for the group, as the leadership is starting to see the light after I pointed out all of the problems with the last few recordings they've done for us.