[andreyvit]

Not necessarily. As long as some mashed pixels of the license plate remain, and assuming different license plates would result in differently mashed pixels, it might be possible to restore the original from the highly compressed image data.

[kookamamie]

From series of images, aka. video, sure. From a single image? Not so much.

In video there is a lot of temporal information and even if the spatial resolution wasn't high enough in a single image, one would be able to accumulate a higher resolution version of the scene using multiple observations.