Cryonics is the practice of freezing a newly-dead body, for a fee, in hopes that death can be reversed and the terminal disease cured in the future. Whatever the medical improbability, let's imagine that part eventually does work. Now to the legal part - future generations won't necessarily want to revive every frozen body. What could legally compel them to?
There's been a question proposing a trust, but to my understanding dead people can't be beneficiaries of one. Heirs, if some exist, won't necessarily want to revive their ancestor (and potentially lose their inheritance). A trust could promise the estate to whomever revives the body, but it's likely that not all estates will keep up with the inflation.
Is there a contract or another legal mechanism that could enforce the frozen body's revival, if medically possible, under existing law?