That all depends on how they do the SSD controller. If its host level management (purpose built software) than whatever runs that will need to be powered up to do reads and writes. Or would all the magic processing be done by a tiny little arm core?
I guess it depends whether they go with a standard nvme or with something lean, soldered on board.
If they have a standard nvme drive, they might simply connect it directly to the pcie lanes on the SoC and cut the middleman. Then the SB would be a normal dumb SB for the usbs, wifi, bt, and the odd.
But if they do a custom soldered on board cheap solution, they still need a chip with pcie on one side to the SoC, and parallel flash interface on the other, so might as well combine everything as the south bridge, with memory.
Third option is a full features SB with pcie to the SoC and nvme to a standard drive. It could still run file system and standby network operations, however the hardcore processing for wirespeed crypto and decompression would still be done by the SoC since it's only required by the game running. Just moving data around is not a heavy burden.
Pcie lane switching is also a thing, the SB could just take control of the pcie lanes going to the nvme when in standby and have the SoC completely off. And when powered on it relinquish the drive to the SoC lanes.
I wonder if any of these choices can be considered "elegant" from their point of view.
