This film pretends to be a remake of the classic slasher film with the same name, despite only having very surface-level callbacks. The sorority setting is just about the only major similarity.
Much like "The Cloverfield Paradox", this film feels like it was made as a separate entity, but had the the "Black Christmas" name slapped on as a late decision in an attempt to market it better, as if this film was afraid of it's own identity before it was even released.