It seems odd that atheists even bother with Christmas. Surely we should ignore it and sit at home congratulating ourselves on our intellectual superiority. Well, I can't speak for Richard Dawkins - like I could get a word in - but most of us love it.
Christmas, like a lot of Christianity and most other religions, has values and virtues that don't require belief in an imaginary friend in the sky to appreciate. "Do unto others as you'd have them do unto you?" Good one, Jesus. "The mind is everything: what you think you become." Food for thought, Buddha. "When you see a person who has been given more than you in money and beauty, look to those who have been given less." Have you just been in New Zealand, Mohammad?
I don't mind being wished a happy Christmas. And I'd be surprised if many refugees, who were recently offered official protection from that invocation, did. They almost certainly want to accommodate themselves to the ways of their new home. That's only polite.
If I were in India and invited to a Diwali celebration, for example, I'd expect my hosts to be upfront. I'd want them to tell me we would be celebrating the spiritual victory of light over dark commencing on the day supernatural beings formed the goddess Lakshmi out of an ocean of cosmic milk. "Goodness, these laddoos are delicious," I would say politely.
I'd feel patronised if they said, "We'd love you to come to, er, our event. Yes, we're having an event and you should definitely attend. There will be eating and merriment. Nothing special. Not an acknowledgement of a millennia-old superstition at all. Just a good opportunity to focus on friends and family."