Sikorsky had been working conceptual design layouts for a 5 bladed S92 hub going back at least 10 years ago. With the original VXX, CSAR-X, and MHP kerfuffle, I think a lot of these upgrades (presumably including the ID-MGB III capable of actual 30 minute loss of lube) fell by the wayside as the 92 had not found a large lucrative customer at that point.