But perhaps it is J. K. Rowling who should get credit for doing the acknowledging. If you write "students are given time machines so they can attend more class

But perhaps it is J. K. Rowling who should get credit for doing the acknowledging. If you write "students are given time machines so they can attend more classes" and no one in-universe points this out as odd, that's Harry Potter. If a fanfiction has someone notice how odd this is, that may bear a greater stylistic resemblance to Terry Pratchett, but the core silliness was still J. K. Rowling's idea to start with...