I ran into a similar problem using a Yocto image. I updated the firmware on the Gen 2 to 1.0.2, but the Linux build was for an earlier firmware (1.0.0 I think). Once I used an updated Linux image eth0 appeared.
The Debian image needs a refresh of the kernel package, which I'm counting on to fix the ethernet drive. I'm trying to get to it as soon as I have a couple of hours.