No. You cannot move when you Iceblock.
Iceblock’s weakness is that your a stationary target that it’s extremely easy to setup a kill on.
Both would be a 150 hp automatically given on death as a second wind. One gives you heal and movement instantly, but you lose your kit. The other is a heal over time, during which time you are stationary but once you exit you have your kit.
It is actually easier to kill a Mei coming out of Cryo than a baby D.va because of this predictability and her much larger hitbox.
How the hell is she gonna wall-off when dead to manipulate cyro?