The linage of the World heavyweight title is a bit of a strange one. Sometimes the WWE recognise it as the WCW title and the long history attached to it. Then sometimes they remember that David Arquette and Vince Russo are former holders and then say its a different title and that it started with HHH.
They regonise the US title's WCW history and they've adopted the old WCW cruiserweight title but the world/WCW is a little grey..ish..