#4 - Dec. 21, 2017, 4:34 p.m.
These two camps do alternate as
Foulpaw mentioned there.
If you hang out in that zone you'll notice that they get attacked and the NPCs abandon the camp until it's retaken again. There's some chat lines and alerts that go out to let you know an attack is coming in and the camp is being evacuated.
There will always be one of them up though :)