https://news.ycombinator.com/item?id=13164392 According to `jdross, purchases are funded with a small amount of equity and the rest with "debt-like instruments" so the taxpayer is still potentially on the hook. But, yes, homeowners don't seem to be at risk.
Unless I'm misunderstanding their model, it is only OpenDoor and their investors that will lose.
The house sellers already got their cash. And it seems very unlikely the taxpayer will end up bailing out a risky startup.