This isn't even that new of a thing. The floppy disk drive sold for the Commodore 64 included it's own 6502 CPU, ROM, and RAM. This ran its own disk operating system[1]. Clever programmers would upload their own code to the disk drive to get faster read/writes, pack data more densely on the disk, and even copy protection schemes that could validate the authenticity of a floppy.
1: https://en.wikipedia.org/wiki/Commodore_DOS