We do not need our bodies once we leave this world regardless of what you think happens after we die. We should be focused on curing diseases and extending the life of living humans. Science would go so far if we used human bodies after death instead of requiring people to give consent to something they don’t need.
No, not till there’s a way to monetize it. There’s no black market for organs, and I doubt there could be one, but do you really think insurance companies and the like wouldn’t start looking for was to increase kidney availability?