Indeed these are wonderful expressions and attempts to re-orient the “holiday season”. But even with such noble intentions, they sort of miss the mark. The expression we should more properly read is “Keep Christmas in Christ”.
It is not so much the Christmas event and what it means (the birth of Jesus), that inspires us to come together and give glory to God, but rather it is the incarnate God, Jesus Christ whose birth that blesses this event and time of year. It is Jesus who blesses every aspect and moment of our life.
Our relationship with Jesus needs to be in the context of loving God with all our heart, soul and mind. This along with loving our neighbour as ourselves, is what can inform us as we prepare for this blessed feast. That like all those called, we should come to worship the incarnate Lord of Glory, made flesh by his most holy mother, as a new born infant, and not to be accounted in any census, or to be apart of some social event.
Unless we keep Christmas (or Pascha, or any other feast or event), with Christ first, we will slowly lose the reason for why we come together. Whether in how we see the world, or how we see the mercy of God given to each of us.
May the Lord bless us and strengthen our focus and work, as we prepare to meet him Bethlehem.