C. Elegans can be already cryopreserved and revived, mice can't.

Keep in mind that any success on small organism doesn't necessarily translate to larger organisms due to the square-cube law: the heat capacity of an organism, or its brain, is proportional to its volume, while the speed at which you can cool it for a given temperature difference is proportional to its surface.

If the temperature difference between the inside and the outside is too high, the outer layers freeze/vitrify and contract before the inner layers, causing cracking. If the cooling speed is too low, you get lots of ischemic damage and large ice crystal formation.
Ice crystal formation can be reduced or inhibited using cryoprotectants, but the slower the cooling speed the higher the concentration of cryoprotectants is needed, and cryoprotectants are toxic at certain concentrations (used by cryonics companies), causing protein denaturation an cell membrane distortion.
The speed at which you can perfuse cryoprotectants is also limited by a square-cube law. In the protocol used by cryonics companies, cryoprotectants perfusion takes many hours.

A mouse brain is about 3,000 times smaller than a human brain by mass, therefore even if someone managed to cryopreserve and revive a mouse it wouldn't imply that the method is scalable to humans.