Assassin Creed Unity crowded streets and seamless transition inside and outside of buildings is a gameplay mechanic. Cpu and memory size limits? Maybe some areas of Uncharted.
Alot of games which dynamically load the game world would have issues with the hdd transfer speed limits and memory limits in last gen consoles, forcing many more loading screen.
64bit precision in No Man's Sky.
The quantity of zombies and physics in Dead Rising 3/4.
Lower playercounts in multiplayer.
Some of your example aren't CPU related and many of this games are able to run on older consoles with some compromises without changing their mechanism too much. We already have great games with great physics on 360/PS3 and also I don't consider lower number of players in MP deal breaker as it wasn't in BF4 for example.