I don’t know if either of those statements are true. Decorating trees was a pagan celebration in many religions, as attested in Jeremiah 10 and in records of Attis cult celebrations and so on. They don’t always connect with sacrifices. I haven’t researched any of these tradition’s connections with calendar dates. Someone may have. There is a lot written on this.

I was reading somewhere that Christmas trees as we know them today, have come down to us from pagan tree worship, and the sacrifice of animals to trees, to insure their rebirth in spring. Is there any evidence tying this to Dec 25th in antiquity?