A friend of mine spawned on the coast and ran to our camp. Along the way, he was looting and found a Child's Briefcase. Upon arriving to our camp, he dropped the Child's Briefcase inside of one of our tents, but not within the tent's inventory in order to take a bag from our tent. The item didn't despawn after an hour. In fact, I can confirm that the Child's Briefcase remained on the ground for over three hours as it was still on the floor of the tent when I reconnected later that evening.
It is unlikely that anybody interacted with the Child's Briefcase as anybody that knew about the tents wasn't connected during the time the bag stayed. And if somebody encountered the tents and interacted with the bag (unbeknownst to us) they missed an opportunity to take much of the high quality gear within the camp.