ChatGPT and Grok say Christmas either does or might have pagan origins, but not that it definitely does not have pagan origins (yes, I know "proving negatives"is very difficult†).
ChatGPT: https://chatgpt.com/share/676c8fd1-b6e0-8005-a86f-d43ac17634...
Grok: https://x.com/i/grok/share/8fQKIFO1WGl3nDVZ6uFaJmPTW
†Grok on proving negatives: https://x.com/i/grok/share/kcHkjqzJ5lx5kMyl4GL0nMuw3