I didn't bother actually looking at the OOP until now but I'm one of the people being quoted, the one who mentions it's probably the Volga. Yeah, obviously I'm not saying Lenin put a bunch of German people there, but that he established the Volga region as its own state entity.

I just haven't really investigated this subject, but the reason they were displaced is that the Nazis used ethnic Germans multiple times as an excuse for annexing parts of countries and sometimes even had the support of a portion of said population. This was also the reason for the postwar relocation of Germans westward.

Part of me feels like Sudetenland, etc. give this a basis even though it seems like a crude solution, and of course both Redditors and atrocity propagandists like to act like they were just put in Gulags or cast into the Siberian wilderness when that is not what happened, but I already have too many ongoing research projects . . .