Is Santa Claus a Fantasy topic? I think yes, but just want to be sure before doing so.
We discuss fantasy here, we don't make it. So I'd say a question about the literature about Santa Claus is on-topic. It doesn't have to be about a specific work, it can explore the related myth and tropes transversally. But it does need to have some anchor in existing works.
Now about your actual question: I don't think it's appropriate for this site, because it's not relating to existing works. And judging by the quality of the answers it received, I don't think it's appropriate for Stack Exchange at all. This is more of a topic for chat.
A bah, humbug in advance.
We have four santa-claus questions so far, and given the time of year, it's reasonable to consider an increase:
- How does NORAD track Santa. How can science-fiction/fantasy expertise provide value here, unless the question was asking how this has been explained in existing works? If it's purely about tracking a sleigh-type object, then that's better asked elsewhere.
- Is Santa Claus a Time Lord. I personally don't consider any "can we fit a character from universe A into universe B" question as constructive (e.g. this Star Trek/My Little Pony one). If it was worded so that it was asking if the Doctor (or another Time Lord) had claimed this in canon, then that would be different, but as-is these seem pure discussion/speculation without value. However, since the others are on-topic, this perhaps is.
- How does Santa Claus get into houses without a fireplace. Closed. As the comments point out, this is (as it is currently written) really a parenting question.
- How to know if a Santa Claus is the real one. Closed.
Maybe these are 'fun', and maybe I am just not fun enough, but I see no value here at all.