Allison, the website does not say that explicitly. Rather, it says that vol. I contains "two fine Mozart rounds", and there is a table of contents listing "Alleluia (Mozart)" and "Mozart's Drinking Round", obviously the well-known rounds KV 553 and KV 560. "Long is our Winter" is mentioned without a composer's name. Mozartian flavour? Well diluted in a staple of church musician's craftsmanship.

The question of (hidden) comment on Nazism and war is more interesting. The Wiki linked by Joe tells us that membership of the Confessing Church alone did not put anyone in prison, let alone concentration camp.