I was suggesting world in motion so as to escape the gravity of the baggage that accompanies "living world" while still describing the player facing feeling of verisimilitude in terms of things happening. A phrase that can describe not just that specific prep heavy approach, but also the other methods of achieving that same feeling.Sure, but the term "living world" was being used to describe a specific approach of heavy prep and the GM conceiving of things that occur independent of the PCs. I was pushing back against using "world in motion" as a sub for "living world" as a sub for this approach -- these phrases accurately describe a number of approaches that generate the same 'feel' in play. Which is what you're saying. I'm just trying to point out that chain of responses, such that your initial response seemed to be offering a new term to describe the heavy prep approach rather than the feel. I don't see much daylight between us, here.
Edit: Perhaps a different phrase that's linguistically further separated from living world might be better...