I remember that one of the "big" things they talked about in their early demo's was, that the party could split up, scatter all over the map and do different things in different places. I don't know if anyone ever used this feature, but combining this with a time system is hard, as you would have to be able to travel back in time when you switch from one patrol to another. I always assumed this was the reason of not having the day cycle.
(Oh, and the ability to throw your boots at an enemy. I remember that one also being promoted as a sign that showed how versatile this game was, in early demo's. )
Maybe these are things to look out for in the upcoming demo's.
I did this at Rosymorn Monastery. My Githyanki Tav and Lae'zel went in looking for the Crèche while Gale and Wyll "investigated" the winery.
What made me think that the passage of time was actually planned was seeing how the sun rolls into its afternoon position when you made the loading screen invisible or how many places in Act III have working lights that only make sense after dark. It could have been morning/afternoon/night with 5e's short/long rest system.
