I agree with @limbicfanatic that removing NPCs and having them have day/night or pathing cycles really only makes sense when you want to discourage interactivity during certain periods of time. In Sea of Thieves, you've got to be able to race to turn in treasure since, after all, treasure isn't really yours until you've cashed it out.
However, I'd go a step further and say, in effect, the People at the Outpost DO live in the buildings that they inhabit. Most of the buildings have second floors or cordoned off sections where, using our imagination, we can assume are the sleeping quarters for the characters. For example, the Castaway Camp has an entire shack where some of the Pirate's Life NPCs sleep. The Tavern has a second floor, inaccessible from the inside (but easily accessible outside). Gold Hoarder and Order of Souls tents have deeper quarters that fade to black. And so on and so forth.
What I definitely do think would be valuable, though, is new settlement types, like Pirate Cities that show a seaside port-town with lots of varied and thematic structures. Or Pirate-run Fortresses/Castles.