Car insurance companies have their problems, but pricing risk is not one of them.
We saw this before -- they used to charge people who lived in high crime areas more money. They had to stop because it turned out that those high crime areas also had a lot of poor people, so the government stepped in and stopped allowing pricing by zip code.
But the insurance companies weren't wrong about the risk -- those customers cost them more. So instead they had to raise everyone's rates to account for the fact that they (rightly) could not discriminate.
I suspect the same would happen here. That poorer people could not afford self driving, and they same anti-discrimination rules would apply.