I have definitely noticed that Harry Potter stuff is associated with Christmas a lot, and I never really understood how it is considered a Christmas movie. I have seen all of them once... I binged them during Covid, so I could have easily forgotten the connection.
That said, I guess it isn't really too far-fetched, there's a lot of Star Wars Christmas stuff out there too and I never really considered Star Wars a Christmas movie. Although, I hear there IS a Star Wars Christmas special out there somewhere.