The same SVG file is rendered correctly when the above mentioned option is checked. While we can discuss about the technical issues here, the more general question is:
Is there a real need to render a SVG image in GNOME / HIG website(s) ? Why not use non-vector based image formats, which should be unaffected by font settings.
I’ve submitted a couple of feedbacks in the past, which I don’t remember the details of, and so don’t know if any action was taken. So, I’ll wait for a while to see what actually happens, if one submits a feedback via “Send feedback about this page”.
Text inside an SVG file can be translated using the existing localisation infrastructure we also use for the application help; this means that the images can be translated by extracting the text, localising it, and generating a new SVG with the translated text. The alternative is to have the SVG, extract the text, localise it, generate a new SVG and then generate a PNG image out of the translated SVG; the additional step is unnecessary.