If anyone else is interested in this, at least for now it seems that the screen and adjacent regions will be updated at the framerate of the game, while the rest of the world will still be simulated at and slower pace, so that when the hero explores the map he will see the consequences of the npcs actions or the npcs fetching things and doing their own thing.
(note that this is my understanding and the actual intention might be different)
Also in day 68 at 1h:26m in the QA to the question
Q. Could you also do something like that for AI where for instance you could impose simple behaviours on top of each other randomnly to make complex and varied behaviour instead of the more common behaviour tree approach?
Casey answers
C. Yes that's actually what I was planning on doing so we'll see how that goes when I go to do it
(this is after making it so that types of entities can have attributes that combine, though for a clear insight it would be better to watch the day 68 vid)