In my experience, many Christian and religious-based stations will only play music that's reflective of the "true meaning of Christmas" in their view - meaning the story of the birth of Jesus and all that surrounds that. Few play foofy Christmas songs, novelty tunes or anything about the image of Santa Claus - primarily created by Coca-Cola's marketing team.
In general, I find that the library of holiday music aired by most stations is surprisingly limited and repetitive, especially the Christmas content found on stations owned by the larger groups. I tend to flip around once the repetition on one particular station has become too much to take, and to get some variety. There are dozens of renditions of many popular holiday songs, but many stations seem to stick with just 1 or maybe 2, in rotation for the entire season. There's really no reason to have "Simply Having a Wonderful Christmas Time" by Paul McCartney in heavy rotation as some stations tend to do annually, and Mariah Carey sang more than just 1 Christmas song. At least one of my favorites from Mariah was only heard for one season, then it seemingly vanished. Some of the most well-done holiday music isn't sung by Justin Bieber or Mariah or even Blake Shelton and Gwen Stefani, but few stations seem to air music outside a relatively smallish group of artists and songs. For instance, a few Christmases ago I was visiting some family up north. It was a few days after Christmas, all the stress leading up to the holiday was gone, I was driving in the early evening and it was snowing a bit. I was listening to a smaller, independent station and the song "Hark the Herald Angels Sing" done acapella by a group called Straight, No Chaser came on and I though it was incredibly well done. I personally haven't heard it aired on any major station since, but it's become a personal favorite.