Under this scenario, the loss of eligibility for receiving a transplant would become a liability of cryonics, even to those cryonicists who are never frozen.

I don't see how this works. If you want the transplants, you drop the cryonics. If you want the cryonics more, you drop the transplants. You pick whichever option is more valuable for you.

Unless you can't drop cryonics and sign up for organ donation once you learn you need a transplant, there's no real loss here, even in this unlikely scenario.