Some questions about the various independent/faction stations on the Metro map

I love the Metro universe, and I’ve loved looking at maps ever since I was a kid. I love this updated map in particular.

I have a question (and maybe more in the comments). What’s the deal with Mar’yina Roscha being an inhabited station when it is cut off from the rest of the stations in the line south of it?

Dostoyevskaya in particular is interesting to me because it references the author Dostoyevsky, or maybe his wife Dostoyevskaya.