This may be a reference to texture streaming. While I've never developed for consoles, I do know that texture streaming on desktop & mobile can be challenging.
Being able to mmap a texture directly from ssd (as if it were RAM), with the hardware & os taking care of all the details, could be a big deal for developers.
Edit: To get a sense of how challenging this can be, see this recent talk from GDC for texture streaming in Titanfall 2: https://www.youtube.com/watch?v=4BuvKotqpWo . Literally all of this complexity would go away if you could mmap textures directly from disk and let the gpu handle it.
To my ears, this sounds very similar to what AMD's "Vega" cards provided for high-end compute. The "High Bandwidth Cache Controller" allows datasets outside of the GPU's memory to be accessed in a transparent way.
I can't find a decent technical article at the moment, but here's a link to the "Radeon SSG," a $7k graphics card that ships with 2TB of solid-state storage attached, designed to be used to process absolutely massive datasets as though they were in RAM: https://www.amd.com/en/products/professional-graphics/radeon...
Being able to mmap a texture directly from ssd (as if it were RAM), with the hardware & os taking care of all the details, could be a big deal for developers.
Edit: To get a sense of how challenging this can be, see this recent talk from GDC for texture streaming in Titanfall 2: https://www.youtube.com/watch?v=4BuvKotqpWo . Literally all of this complexity would go away if you could mmap textures directly from disk and let the gpu handle it.