I suspect factory firmware is present on the device alright. The TDK programmer's guide doesn't state it explicitly, so it's a gamble.
In any case, like I said before, it really helps to read the programmer's guide for the device. It clearly indicates, for instance, that the I2C register definitions are firmware -dependent, so whatever registers you try to read/write need to be correct for the firmware that's present on the device. Again, the Sparkfun website links to the programmer's guide: https://cdn.sparkfun.com/assets/8/f/3/f/4/AN-000175-SonicLib-Programmers-Guide-v1.0.pdf
This is not just any old I2C device with a straightforward interface. It's more flexible, but as a consequence it's also a little less forgiving of the "nah, I'll forego the reading and just wing it" approach.