So I was standing in the town hall, and I realised that the names of some of the NPCs looked terribly familiar.

I'd never noticed this before, and I bet not many people have. It is on the Wiki, but I'd never gone to the individual add's pages before.
So, it kind of makes sense. I mean, Karazhan isn't that far from Duskwood, and Darkshire has been overun by all sorts of undead and worgen nasties, and there's the link between the worgen and the black riders of Deadwind Pass already.
Duskwood has always been one of my favourite zones, I think because of the storylines there that all work together and (when I take time to read them) are well-written and make you feel something for the characters here. I also love the Scythe of Elune line, I always take the time to go and start that one in Ashenvale so I can finish it up at the same time as the other worgen quests.
So, did those guests go there when Moroes and Karazhan were still alive(ish)? If you just go by the book, the Last Guardian, nobody but Moroes and Cook were there with Medivh until Khadgar came. The game seems to change that a little, having a whole host of guests and servants. Perhaps these are before Medivh? Maybe on dying, Moroes made friends with the local ghosts and invited them over for tea and crumpets?
I have no idea, but it's cool nonetheless.
