Using a religious objection for this seems appropriate. The belief that you can live forever by if your body is frozen after death is more or less the same as the belief that you can live forever if your body is intact and you worshipped the right deity.

I don't want to stray too far from the original topic, but your equivocation is unwarranted. Unlike religions, cryonics actually has evidence behind it. Modern cryoprotectants allow for accurate preservation of brain nanostructure. Axons and even synaptic vesicles are kept intact. In fact, Alcor's cryopreservation protocols have already been used successfully on small mammal organs, such as rabbit kidneys.[1] Kidneys are harder to preserve than brains, as they have less vasculature to allow saturation with cryoprotectants.

Does all this mean that pumping a brain full of cryoprotectants and cooling it to -196°C will preserve its memories? Possibly, but we don't know. Cryobiologists and cryonics researchers readily admit this, and they're working to find the answer.[2] If that sort of thinking is religious, then call me a zealot.

1. http://www.21cm.com/pdfs/12FahyORG5-3%5B1%5D.pdf

2. https://vimeo.com/22766034 Starting around 33:05, Dr. Brian Wowk talks about memory preservation. He's quite frank about the fact that there's not proof, just a good likelihood that current methods preserve memory and personality. Then he outlines some next steps for research.

There's not yet evidence in favour of brain function being preserved though, even if the structure seems somewhat intact.

Anyway, many electron microscopy studies show that even in ideal laboratory conditions, cryoprotected tissue always has some amount of freeze damage to its structure, despite some areas being beautifully preserved. Humans have it even worse than the average lab rat, as there is always going to be a greater amount of post-mortem delay - during which the brain is undergoing ischaemic damage.

Cryonics is an interesting area of research, but the claims of being able to preserve memory and personality are really quite unfounded at this point.

May I respectfully suggest that if the capability to revive a cryonically preserved human does not currently exist, then current proponents of the practice are placing their faith in the possibility that the capability will exist in the future?

Not a religion in the traditional sense, but as humanity currently lacks the ability to reproduce the intended result, the practice relies highly on belief.

Regardless, if claiming a religious exemption from autopsy allows one to "hack" the legal system to achieve ones goal ... why not do it? I have a hard time finding a possible victim in such a circumstance.