Meanwhile The 'Western' allies were also fighting across the East Asian and Pacific theatres, and had opened the Italian front in Europe the year before.

It's absolutely true Russian participation in the European war was decisive, but Europe wasn't even the only war going on. There's a good argument there was another war active on the other side of the world simultaneously in which Russian participation was minimal.

Anyway the whole premise of the criticism is facile and self-serving. Russian war achievements are entirely worthy of their own celebration and remembrance in their own right. They should not more overshadow the achievements in Normandy than those commemorations should cast a shadow over the African campaign, or the invasion of Italy and the contribution of soldiers who fought on those fronts.