[none_to_remain]

I've read about the NYC mesh in the past, I don't remember it being disconnected from the wider internet?

[capableweb]

Usually the meshes have parts of the network that is connected to the internet, and you either automatically get access to those nodes so you can route via them, or you can request access to be able to reach the wider network.

Really depends on the mesh, I don't know the specific answer for NYC mesh.