Christmas is about joy and different things bring joy to autistic people than to non-autistic people. A tub full of swirling, colourful ties or a shiny, tinsel Santa may have given him a moment of joy, even if less so for you. What a challenge for his parents and for you all.
I hope this is the year he joins you, but what matters is there is always a place for him, at your table and in your heart. I know there is.