NG+ Alternate universes like Evil Self, the Empty Nest map marker remains disabled and 00263981 LC006_LoadDoor_Ext is inaccessible. This would seem like the right thing to do, only there's really no point and there's the Ashta Tamer to collect. The interior of the cave is completely blocked off inside where the artifact would be found and there are no traces of there ever being one in there, so it's kind of a lost location. There's also no occurance of Shaw showing up when you leave the cave. These would more than likely need to be scripted to unlock and enable.