I suppose there's an tiny chance they have an idea Raki could pull off. Although if it needs to be Raki, it would unfortunately suggest it's connected to Clare, which would again mean Raki's role would be secondary, nothing but a trigger. Who knows, maybe they just want to chat, seeing how Raki knows more than many claymores or old awakened ones. But like you said, there's not much room for humans in all this unless these dudes have discovered something groundbreaking.