Sure, there is a history of Shar involvement in the area. That doesnt contradict my suspicions at all. Infact it strengthens them because Shar would obviously have a very good reason for vengeance on that whole area and the Grove and the Druids.
The Blighted village destruction is more recent, (i think) and i wouldnt be surprised if Shadowheart was one of the children that started missing from the village - also a bit of info found in one of the written documents you find there. I think its the diary that gets Shadowheart strange shaking.