Whenever I'm patrolling the plaguelands and I'm moving from Lord's Watch to Giant's Husk, Ghost will say something like, "The Fallen are Deploying a Walker" or "Fallen artillery inbound, are you ready for this fight?", making me believe an event is starting in the area I entered or the area I just left. It's getting annoying.
I'm surprised that more people haven't said this sooner. I just quit paying attention to my ghost altogether. He's only there for the storage space and ship access.