News World's first hybrid CXL device combines flash memory and DRAM — storage tiering comes to remote memory over PCIe

Sounds just like the memory add-in cards from the IBM XT compatible days (mid 1980's). I believe you had to load a driver to allow DOS to access the RAM as paged memory due to addressing issues. Yep, even then, engineers were not thinking ahead.
 
I wonder if it has a mode (+ capacitors or battery) that dumps the DRAM contents to NAND, upon power loss. If you limit the usable capacity just to what fits in DRAM, that would make it behave just like Optane, @jkhoward .

Except, DRAM is an order of magnitude faster than Optane. Given how expensive Optane was (nearing DRAM prices), it would struggle to compete with such a device.