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.
The morgue bodies may not have as high quality of organs or may not match genetically. If a billionaire puts a bounty on a liver that fits them genetically and has barely been abused, someone is going to be looking to cash in.
I wish I could live in that timeline where all morgue attendants got a page when the world’s 1% needs a good looking kidney hahaha.