Totally agree. I think voice actors will be even glad to take part in work on this game again. I think they have seen audience reactions of their acting in media (especially V, Panam, Judy).
Indeed. Often, because the story and DLC is alredy pre-planned, the lines are recorded in advance with the bulk of the main game anyway. They just need to do the quest design, level layout, animation etc and put it all together as package.
It just depends on what they've already got planned in the works as to what we'll see initially.