I have actually been wondering this myself... because truthfully I don't know. If they do disappear permanently, that's a great way to finish off a faction. One by one. I'll have to test for this.
Right now I am trying to fix a problem. The mod crashes when i enter the arena. I thought I hit the item limit. But removing the items doesn't stop the mod from crashing. However, cancelling out a particular trigger in the "triggers" module, that jumps to a menu, does fix it... it makes no sense, so I am going to have to research this one.