I think character names weren't redacted because it was (& is) pretty difficult to identify somebody with just their name. You need a location to go along with it, at the very least, unless we are speaking of the royalty I suppose

I haven't read Frankenstein in a long time, so I don't know if it's the same there, but in Austen's novels I feel place names are "redacted" when they're associated with negative things and left in place when they're associated with positive things. Kinda like how our newspapers would go "Florida Man threw an alligator at his girlfriend" vs "Steve Irwin, the famous Australian wildlife educator, and his wife Terri spent their honeymoon trapping crocodiles in the wild".

So in Pride and Prejudice, we know Mr. Darcy is from Pemberly, Derbyshire and Pemberly is near the town of Lambton. That's basically pin pointing his identity - but that's okay because he has nothing to be ashamed of/to hide so his identity need not be protected. On the other hand, Wickham's regiment is always _Shire - because he is is a scoundrel and thus his identity needs to be protected/censored.