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.