I don't so much see them continuing the Job storylines as much both class and Job storylines. Remember, Jobs aren't leveled, they are equipped. Classes are leveled. As such, it's the classes that will be getting the most attention. More abilities, more traits, more cross-class slots. With the level cap raising only 10 levels we'll likely see two class quests and one Job quest. This is because Job abilities take up a cross-class slot and the classes will only be getting two more if the pattern holds. Would be rather limiting if your Job took up both slots.