Good catch! I tried uninstalling librsvg2-common and the icons went away again.
I wish I noticed this before making my bug report. My heart goes out to those with unusual architectures, I ran Linux on PowerPC on my only computer from about 2001 to 2007. That was certainly difficult at times. But... I think the best solution is to make librsvg2-common a Depends of inkscape. I think Recommends is for things that enable features, but are not required to enable primary thing the program does. The primary thing inkscape does is provide an editing gui, and it cannot do that without librsvg2-common. If having headless inkscape on unusual architectures is important enough, then a inkscape-headless package could be built. If that use case is not important enough to warrant a package variation then I would argue it's also not important enough to break the inkscape gui for everyone who doesn't automatically install recursive Depends dependencies... though I understand that folks turning off auto-install of recommends are a minority too. That said, making librsvg2-common a direct Recommends of inkscape would have saved me a lot of trouble, and I would appreciate that too. P.S. I know turning off auto-install of Recommends sometimes requires me to put in a bit of extra time, but I hope that at some of those times I stumble across something in the debian packaging that can be improved, so this extra time I spend is occasionally useful to others. I turn off auto-Reccomends because many many packages put stuff in Recommends that I don't need, and in the rare cases that I have to install a Recommends to get a feature I want, it's a direct Recommend so it's easy/quick for me to find and install. P.P.S. It seems like rust is here to stay, I hope that folks with a passion for new/unusual architectures will put their energy into getting rust support for their architecture of choice.
