I just thought of something.
So, if I were to write a fanfic about modern day Hogwarts, it would be filled with British references. Like, our music etc. Most of the kids would be half-bloods, so it would make sense that they understood Muggle references.
Like seriously, I can imagine Harry’s son, James Potter II, going through a phase where he tries to become a roadman thanks to his muggle-born friends.