Looking at that, I rather do think that it is, indeed, a glacial cirque. I'm wondering where the glacial moraines would be. I don't think it would be difficult to locate them by looking at some topo maps or, perhaps, scouting around points where a terminal moraine would have been located.
If there was a local glacier there, it looks like it was a rather big one. Far wider than some of the other glacial cirques I've seen on eastern mountains.
Bottom line is, I think it really is evidence of a localized glacier that once flowed here in North Carolina!
Photo by Andy Kunkle.