Yes, I'm aware of that. My point is though, everything is going to quadruple in size -- particularly graphics in games.
Not necessarily. A lot of 3D games especially already used higher resolution textures that simply got downscaled anyhow. These probably wouldn't even look better.
Apps simply using UIKit widgets probably wouldn't quadruple either since they don't have "graphics", only references to things like UIButton, UIlabel, etc...
So there's no set rule for how much more storage apps would occupy, if some even do.