The Obama administration has directed the military to not allow personnel to say “Christmas”, in spite of the holiday’s status as a federally-recognized holiday.
The reason given by armed forces officials is that not everyone celebrates Christmas and that out of respect for them, military members should refer to Christmas celebrations simply as “holiday”-themed festivities.
This prohibition comes in the context of a wider push for political correctness in society in general and the military in particular, as evidenced by the recent reprimanding of Navy Chaplain Wes Modder for simply discussing religion, as chaplains are wont to do, with military personnel.
See how servicemen have reacted to not being allowed to say Christmas at the link below:

Brandon Smith
Look out! It’s on “snopes” it HAS to be true lmao
This IS America, CALLED FREEDOM OF SPEECH, AN RELIGION, AS LONG AS IT IS PEACEFUL!!
Bacha bazi boy
Muslims don’t say Christmas.
You can’t Threaten anyone, like terriost’s DO!!
Muslim idiot!!
Hey Obama nut case you cannot score of the First Amendment
There is no way a Christian would forbid saying Christmas. A blessed Merry Christmas to all, and that includes you, Obama. Merry Christmas to all our soldiers and veterans.
This guy is really mental he’s like a black$#%&!@*but only he is worth s***