Does it even need to include fancy memory?
Compare the average speed of a common 2.5'' 5400 rpm HDD (120 mbps) to a modern SSD (3000 mbps+) and the results are as good or even more impressive than what has been shown with Spiderman in the article. So far, what has been demonstrated and implied is consistent with a standard SSHD solution.
The problem with using SSHD is, the benefit of having high speed loading data will not be directly build inside the system. Because all the performance and benefit of fast loading data will only be be attach to the SSHD, and if someone by means try to remove the hard disk and replace with normal HDD all the benefit will be loss (or even worse , PS5 games will not working) .
Actually the statement from the article explained on how the fast loading benefit will be the standard for PS5 performance, this require a dedicated bus/nand flash ram/ memory soldered directly to the motherboard. And it will be using the same principality with how intel optane work on the PC, but of course PS5 will not by any means using Intel Optane as the nand flash memory. I am using Intel Optane as an example on how SSD/Flash memory will work on PS5.