Yep that's true, you could count their labor towards the overall due reparations.

As well as loss of substantial amount of German property to Soviet Union and its satellites. In effect, Poland was shifted left on the map by 200 km or so, and the space and property claimed by U.S.S.R.

Also, lots of industrial capacity of East Germany was moved to U.S.S.R. For instance, my dad's first car was a Moskvich 401, which was effectively the same as the pre-war Opel Kadett K38 whose plans and tooling were transferred to a plant in Moscow.

I have a very nice KMZ Industar 50-2 camera lens which has similar heritage to that car, a Zeiss Tessar design made using plans and tooling moved to Moscow from Germany.