Imho, would make a lot of sense. A chaos warrior pre order dlc plus a rework. Adding a Khoorne and Nurgle (for example) legendary lords to the WoCs, while TW3 starts with the other two gods for the demons of chaos. It would be a way of having the 4 god's on TW3 from the start.
The roster is lacking so many things that making a Lord pack only about the WoC is perfectly possible.