Inclusive? Holiday Concert

I was speaking to an Associate Teacher today while the teacher in training was winding up her lesson. Mrs. S was impressed with the teacher candidate involvement in the holiday concert last night. The student teacher had rehearsed a French song with the students and led their performance of the song during the concert. But Mrs. S went on to say how difficult it is for her to hope in the future of our schools in view of the direction of inclusion. The word "Christmas" and songs related to the traditional Christmas were not included, but reference to Ramadan and other cultural festivities were celebrated. She mentioned that in her opinion the freedom of access to education and freedom of religion are part of a Christian heritage and set of mores and laws. Why exclude the Christian celebration then? It seems the dominant religion of the past, though having its faults, is now silenced such that the strength of its tenets are lost.