Interesting... you may have your tone controls locked out but do they ? The smiley face may be on the other end. One of my favorite stations runs a contour for some content and it sounds great. Not flat, true, audiophile but great. So what ? I listen to the music, that's what matters. They play some great jazz.
Not dumping on your "find' but I spent lots of years in broadcast FM and never ran across a station that didn't shape the output in some way. Compression was to save RF power and enable greater distance / increase coverage. With so many stations having repeaters, no need to anymore. Roll the top off, boost the bottom a bit and sound good. It's the classical format stations that go gently. On shared format stations, the contours are programmed to change on a timer system (convenience) and sometimes you hear it happen. The last one I worked at had seven programmable EQ's and auto switching by time.
No, I'm not dissing FM. It's still my favorite medium. I just understand it.