That sucks and also sounds like snake oil. World size has no bearing on gpu performance. If they want to simulate people in the other side of the map with full ai or something it might affect cpu but I can't imagine of a context other than an mmo where that might be necessary. And it's not like ubisoft's games are so big that they can use the cod excuse of reducing size neither.

Reading about it makes it sound even stranger. Offloading audio to the server means the audio can be dsynced from the video based on internet jitter and requires some artificial input latency (in addition to the internet latency) to compensate. Same thing with most physics. If you're streaming those parts, you might as well make it a full on streaming platform, especially since graphics are more expensive than audio or physics anyways.