Many states in the US switched from opt-in to opt-out for organ donation. Usually we get upset about such tactics, but this change seems to have been widely supported even though it is a form of coercion and has informed consent issues.
Quite a tangent, but what if we apply this logic of informed consent to property? If a person without a will dies, should we leave their house abandoned until it decomposes? Automatic organ donation is like probate for bodies.
Indeed this is one of the big considerations of adoption or organ donation. Both revolutionized their respective markets: trafficking and involuntary organ trade. To say nothing of abortion and gay marriage - two much desired things in the US which nonetheless revolutionized the market for unethical embryo termination and involuntary marriage.
Kinda like prostitution where it has been legalized, in which the availability of ethically sourced human bodies (i.e., from licensed brothels) drives up the demand for unethically sourced bodies (sex trafficking).