Why would a parent know what was going to be in the whole school's Christmas program? Sometimes one grade does one thing and another grade does another thing. Why would the parent of a first grader know or care about the songs that the fifth graders are performing? Until the night the whole production is put together?
I have no clue what songs are in the various musical productions that our children are doing in school. I have asked one of them, but she just smiles. I'm not at all concerned either. Last year's "holiday" program had all kinds of songs. You could tell which ones weren't traditional Christmas/Santa songs. Nobody knew them well.
Well, I am able to get the program ahead of time. The point is, if a parent is concerned that a school is banning certain Christmas songs, they have an opportunity to address it. This story sounds like the school did not prohibit such yet the parent went running to some organization to complain.