descendants of the Polish officers who were murdered should also be compensated for their tragic loss
Absolutely right!
I believe the claims are for the time period after September 1, 1939 (property ownership changes caused by WWII).
Poland was a double victim of this war, first attacked by Germany and Soviet Union in 1939, and left to fight alone despite international
treaties, then again sold out at the end of WWII and given along with Cental Europe to Soviet Union as gift for defeating Germany.
There was no free Polish administration in Poland until 1989. The legal Polish goverment in London was delegalized by Western powers in 1945.
The first Polish administration in 50 years implemented legal procedures for former property owners that work very well.
There will be no summary 'reparations'.
If anybody needs any convincing, please look at Swiss claims.