Interesting but not entirely accurate. Moldova has not existed as a state until 1991, after the dissolution of the USSR but it shows up on the map after WW2.
The great thing about open map projects is that they can be updated, and store a historical edit log along with discussions and sources for each change.
As with other community projects such as Wikipedia or OSM, OpenHistoricalMap relies on keen-eyed volunteers such as yourself to improve their database!