I had been sitting on the same thought for the last few days having just gone and defined Audio Regions on a few songs for testing. While it's nice that the "mini scrubber" (song progress bar?) takes on the colour segments of the audio regions, it does sort of seem redundant, but I can see pros and cons.
If you use Audio Region Controls AND have quite a few defined, they will scroll off the page so in that situation, you don't get to see the entire song start to finish - the song progress bar will always show the entire song. That may, or may not, be important for someone.
If you use Waveform, it always shows entire song so no problem there.
Either way, I do find it a bit distracting have all the coloured buttons of the Audio Regions/Waveform regions, and then offset horizontally, the colour segments on the song progress bar. A bit too much colour on the screen, but that is a personal preference.
I'd be happy for the song progress bar to revert to a single colour if Audio Regions are defined.
Removing it entirely (in that same scenario) I'm not so sure about.
