I remember getting this really hard for His Dark Materials as a kid. I had developed a huge crush on Lyra, finishing the books was like a break up

If true, that would be fascinating, especially considering how many of his contemporaries started doing it just stylistically - rather than for functional political reasons. Someone else here mentioned that it is sometimes called the "Dostoyevsky Dash" suggesting maybe he started it.

haha too good.

So its versimilitude? Frankenstein is framed as a series of letters so I guess that kinda makes sense, it just seems like the choice is so arbitrary, because its not like any character names, or even other place names are redacted.

Lol, I mean you could say that about almost every detail of a story. The whole thing could be dashes except for the bare bones events at the core. Why single out specific place names? It raises more questions than it answers