It's safe to assume they were there on ministry orders, even if they were some form of controller to check up on vehicles.

[ And that's the thing that forces Roland to go in circles. Each of their motives are unknown - the ministry could be just as responsible for the events of the past as the train itself, and the crew that's left behind. And just like Tidus says, they're just along for the ride. An illusion of choice, of power. Feeling like they've got things under control when a push of a button from the other side could put them through hell. It's happened, right? Void storm, visions, memories shared without consent... ]

I'd like to think that broadcasting voidsickness is just the train's way of manipulating us to stop snooping. Stop wondering about our circumstance and...live nicely on the train. Listen to some music. Read. Relax until our next stop. That's how you get voidsick, right? When you can't relax.

[ Yeah, that's a sore spot for him too. One of the very first things he's wondered about himself, worried that he'll lose more of himself than he's willing to let go. ]