Re: So... how is this different to swap on an SSD?
"so they can bypass Linux's house of cards"
The house of cards is built that way because it has to handle everything that's thrown at it. Swap has been a standardised interface on *nixen for nearly 40 years and is well-overdue for heavy maintenance.
The reality is that "swap" as we know it has been a dead duck for a number of years (if you look at most non-choked systems you'll find they've pushed trivial amounts out to swap. Ram really is staggeringly cheap these days) and a system which "needs" more than 1-2GB of swap is a rarity, because the effect of hitting any form of drive interface in anger makes your machine leap back to the 1980s speed-wise(**), which in turn makes justifying more ram an easy decision. 32GB in a desktop is cheap. 64GB only slightly less so. Putting 512GB-2TB in a server isn't mortgage material anymore either
There's no real secret sauce here and quite frankly the way WD & Seagate have treated buyers over the last decade-and-a-bit means they'll have to try a lot harder than this to convince me to buy their solid state products - especially when they're pushing it in a 12nm format that everyone else backed away from due to it having limited endurance and poor speeds (Hint:There are only so many electrons you can fit in a 12nm cell and it's getting towards "you can count them individually")
(*)except for the ones which hibernate to the swap partition, but that's not quite the same thing as actively banging on it)
(**) It's not helped by more than a few "really fast, honest guv" NVME drives being flogged by name brands who should know better *ahem*HP*ahem* turning out to have write speeds on par with (actually, worse than) 2011-era consumer sata-SSD drives and only slightly better than WD's old Raptors.