I didn't interpret their comment as suggesting that modern consumers would be familiar with a floppy disk, but instead was pointing out that regular consumers in the past often handled floppy disks, which made a good case for it being a common symbol at that time, but the same idea doesn't quite work for modern day consumers who don't often handle SSD's, so it may not make a good replacement as a symbol.

That would suggest that perhaps there is a more commonly recognized object that can be represented skeuomorphically. Off the top of my head, an SD card may be a good option.