Why? Because the the KKR lawsuit and its implications and other lawsuits. If GS violated SEC rules, that goes beyond the clients KKR's immediate claims. If kickbacks of any kind occurred during the "fire sale" that will have implications. If the new SUNE is proven to have hidden or lied about assets worldwide, that will have implications.
It's not just about the shares, it's about years of litigation against SUNE, the new SUNE, its officers, some of the other banks involved. etc.