Yes and no. The video Christmas message is a tradition from the sitting POTUS and FLOTUS. So, yes, this part is political tradition. I happen to also believe the current POTUS and FLOTUS are speaking their personal faith from their hearts.
Don't take this personally, but Netanyahu is not. He's sending a politically expedient message, as he does during Ramadan.
IMO, it would be more "wow" inspiring if the PM failed to send greetings at Christmas (or Ramadan).