We haven't actually been to the Pearl disco yet (other than during the day when we were visiting from DRM) but given the repetition we've seen at DLC and DRM and the similar comments about Pearl, it seems safe to comment
Back in January we were at DRM and we went up to the disco fairly early while most people were still watching the live band that was part of that evening's entertainment program. We made a request to the DJ for a song, probably Professional Widow or something else involving Armand van Helden, and they played it, and then proceeded to read our minds for the next half hour while we were pretty much the only two on the dance floor. We went to sit down when he put on something we didn't care for, and he stopped it and went back to more of the late 90s early 2000s electronic dance stuff that we greatly enjoyed. However, as soon as the disco started to fill up, it quickly went back to the same songs you'd hear every other night. So we moved into the playroom...
So we guess what we're trying to say is that the DJs are quite capable of mixing it up, but for whatever reason, they don't. It would be interested if they experimented on different genres each night, e.g. modern top 40 one night, followed by an 80s night, etc. But as BubbaCal says, it's hard to complain too much when the result of us not liking the music means we just get to the hot tub sooner.