Are you saying we don't know that it preserves information at all?
I know of no evidence. Closest I know is the promising result that a percentage of pinewood nematodes (a favourite of cryobiology researchers, having about the simplest known nervous system that is definitely a nervous system) survive cryoprotectants and vitrification and, if they survive, go on to parasitise pinewoods much like they did before. (E. Riga and J. M. Webster. "Cryopreservation of the Pinewood Nematode, Bursaphelenchus spp." J. Nematol. 1991 October; 23 (4): 438–440.) Preserving a neural network is of course the holy grail. But this is getting way off topic for a blog about the art of human rationality.
I recently found something that may be of concern to some of the readers here.
On her blog, Melody Maxim, former employee of Suspended Animation, provider of "standby services" for Cryonics Institute customers, describes several examples of gross incompetence in providing those services. Specifically, spending large amounts of money on designing and manufacturing novel perfusion equipment when cheaper, more effective devices that could be adapted to serve their purposes already existed, hiring laymen to perform difficult medical procedures who then botched them, and even finding themselves unable to get their equipment loaded onto a plane because it exceeded the weight limit.
An excerpt from one of her posts, "Why I Believe Cryonics Should Be Regulated":