In most cases, signing up for cryonics and signing up as an organ donor are not mutually exclusive. The manner of death most suited to organ donation (rapid brain death with (parts of) the body still in good condition, generally caused by head trauma) is not well suited to cryonic preservation. You’d probably need a directive in case the two do conflict, but such a conflict is unlikely.
Alternatively, neuropreservation can, at least is theory, occur with organ donation.
Not that it isn’t interesting, but it seems confused, and somewhat trivial.
Trivial, because it basically says: Keep in mind that the map is not the territory applies even if the map is a scientific model. A good thing to keep in mind, nevertheless.
But in the details, you seem to misunderstand some of the problems “mathematics appears to have perfect conformity with reality” is, as Vladmir Nesov points out, exactly backwards. Mathematics qua mathematics has no relation to reality, and (properly) makes no claim as to reflections of reality. Your linked article, on the surface, is perfectly in line with classical incentive economics: remembering to take meds is costly, so some people don’t do it. Give an incentive, and more people will do it. Not that there aren’t important flaws in the perfect rationality assumption, and some of them show up beneath the surface of that behavior. But show it to computer programmed to do classical economics, and it will happily calculate marginal costs of remembering to take drugs, etc.
Further, you seem to miss some of the important roots of the problem. Economics is not the only discipline where good models are lacking (turbulent flow comes to mind). But it’s easy to create a turbulent flow in a laboratory. So, is it the difficulty of experiments that cause problems, or the complexity of the phenomenon?
Or is it lack of self-awareness or honesty? Do economists imagine they understand the economy better than aeronautical engineers imagine they understand flow? And if so, why?