When I was young and had a super nintendo I loved playing Super Mario RPG.
I’m playing the remake and I’m at the scene after defeating Valentina. Mallow goes into the castle and Mario was left standing outside.
Back then I didn’t know why Mario pulled out an umbrella and it rained. I just realised after 20 years of playing the original that Mario knew it was going to rain because whenever Mallow cries it rains; Mario knew that Mallow would get all emotional when meeting his parents for the first time.
Blew my mind.
I mean, it’s definitely at least intended as a play on words. And Knockturn Alley kind of works at least, because it’s meant to be a dark/shady street, it’s specific name being “Knockturn” rather than “Nocturn” works well because its also, functionally, directions. You knock to get into Diagon Alley, then you turn to go down Knockturn Alley. But yeah, the name Diagon Alley seems to exist exclusively for the sake of the word play, potentially even just to set up the mispronuncuation with the flu network later on the series.