I have students in my public school class that don't celebrate Christmas. My end of the term parties have Christmas cookies if the kids bring them. I don't do the Christmas games and stuff we did as kids, because honestly the kids would rather play with their dolls, legos, handhelds and my Ipads, while eating their cookies and chips. Many of the parents of kids that don't do Christmas, let their kids stay because it is a end of term party not a over the top Christmas party.
Sent home a note. Got a note back that I was excluding Student because they are Christian and they would be donating chips but pulling their kid out that day to go to his sister's room. Where they will be doing similar things but that teacher used the word Christmas in the letter.
I admit that I'm probably over thinking fairness on this subject more this year. I filed a civil rights complaint about these sermons that an administrator was sending out on school email - quoting the Bible, telling us we had to live and teach by these principles in these quotes. The district and the administrator got their hands slapped. It was supposed to be anonymous but I'm pretty sure one of the administrator's pets figured it out and told him.