Area/BGM music should be mono. You've got mushroom speakers scattered all about in bushes, and ceiling speakers in lobbies, hallways, bathrooms, etc., that all fire upward/downward in a 360° pattern, meanwhile listeners can be anywhere near or far, so there is no way they're ever going to hear anything resembling stereo.
You can put a stereo CD into a five-slot player in a hotel, by the way, but if there is only one output going to all eleventy-seven speakers located throughout the building, it's still going to be mono sound as far as the listeners are concerned.
One thing that Disney does horribly wrong is that they do not process the tracks that they are pulling from various sources through a Dynamics Processor (AGC/Compressor/Limiter), so their Area/BGM volume levels end up being all over the place. That is a serious "no-no" and they should know better. Unfortunately, there are all sorts of professionals who don't know a whole lot about audio dynamics. Radio and TV stations, by the way, are required by law to use Dynamics Processors.
Unlike the people who go to great lengths to exactly duplicate Disney's Area/BGM loops down to the millisecond, warts and all, I actually run the tracks through a Dynamics Processor, and I also add intelligent crossfade points (silence between tracks is usually considered a "no-no"). I end up with the same music, but mine sounds a whole lot better.