I guess they are viewing RAM versus persistent flash memory as just another level of tiering/caching, and believe their swap is so good that it all blends together.
I think this is the correct long-term view, as persistent solid state memory gets better and cheaper. The old 20th century memory hierarchy, with nothing between RAM and spinning platter hard drives should fade into the past. As technology changes, this is sure to be an obsolete model of the world that no longer fits.
iOS doesn't do "traditional" swap though. Once memory runs low, apps will be warned and may be booted out to free some up. It's up to the apps to then persist their state to the solid-state storage.
I think this is the correct long-term view, as persistent solid state memory gets better and cheaper. The old 20th century memory hierarchy, with nothing between RAM and spinning platter hard drives should fade into the past. As technology changes, this is sure to be an obsolete model of the world that no longer fits.