Head Canon:
Tyson doesn’t celebrate christmas. Having grown up in a Jewish household he didn’t as a child and without a family he sees no need to now.Unless he knows that someone definitely does celebrate the holiday Tyson doesn’t both getting them a gift or a card as he knows that most people would then feel obligated to get him something, and he doesn’t want anything*.The only difference is that he is more charitable, though only because it is nearly impossible to turn a corner without finding a donation box set up specifically for christmas and Tyson will always give if he has money on him at the time.
*That statement isn’t entirely true. There are items that he does want but he’s has never been in a position where he has been lacking money. With access to the family fortune Tyson doesn’t need to wait till Christmas to get something he wants.
Even then he doesn’t buy all that much. He limits himself to buying one book a month and, unless it was a digital book, at the end of the month the book will either be placed in the library at the family manor or given to a charity shop.