I think it would be down when the main server is, that would make sense.
well. yes and no. the basic server softwares are simpler compared with getting a decent npc interaction.
having a separte piece of software, it makes it simpler to do things with the npcs, add remove, tweak, etc. then having to work with the server itself. and if you manage to crash a npc, it means you don\'t crash the whole game. and a whole bunch of other things that i can\'t think of right now.
a dev will probably correct me if i\'m wrong. but, it feels like a correct answer.