USSR tried to hide all the "gory" details of WW2.
For example, Babiy Yar (a place in Kiev where Germans killed tens of thousands) was a garbage dump until 1970-s.
Or (which is ironic, given their "Nothing is forgotten, nobody is forgotten" motto) - they didn't search for the fallen soldiers. Probably because they feared that there will be too many Soviet medallions compared to Germa ones...