Do you actually know what the module is built around or are you just jumping the gun? It's a name for a module, that's all. What's at the heart of the module is what counts, and from reading around I gather it's a module designed to help understand contemporary society (something which in an Educational Studies degree is actually quite relevent). They're not going to have questions on the exam paper such as "How old was Harry when he got his wand touched?" or "How many rooms are there in Hogswart?"
It's a module using Harry Potter as a case-study and a window into the real world. Off the top of my head, they could for example be looking at and discussing why exactly the story is so universal and popular, which could include looking at psychology, collective culture and shared history. It could also be looking at universal aspects of all storytelling, etc. Then of course, we could also be looking at how the story was sold and marketed to the world and how exactly the world reacted to such dissemination. It in turn could then turn to look at the unanticipated fantasy tourism it's created and the new economies as a result. There's a lot of genuine complex issues and processes which can be explored.
Just because the module's got a stupid name, does not mean it's banal. It's a fancy name to grab cheap attention. An institution such as Durham is not going to have a module or a whole degree devoted to the ins and outs of the story of Harry Potter. It's easy marketing, that is all.