It's an valid issue, those of us who worked back in the day on GD/DVD,etc games really ran into bad loading walls if we didn't duplicate data for straight streaming.

Data-sizes has continued to grow and HDD-seek times haven't gotten better due to physics (even if streaming probably has kept up), the assumption isn't too bad considering history.

It's a good that they actually revisited it _when they had time_ because launching a game, especially a multiplayer one, will run into a lot of breaking bugs and this (while a big one, pun intended) is still by most classifications a lower priority issue.