Again in campaign terms, lords originally added in TWW1 are only playable in Mortal Empires, although some of them have been changed (eg: put in a different starting location or faction) for the second game. Scroll down further for another table showing that.
First game lords
In Total War: Warhammer II, first game lords are all playable in the Mortal Empires campaign. However, there has been many changes and updates to them. Click "expand" to expand the table.
In this table, "base game" means the first game, which is required to play Mortal Empires.