> The way I see it is the cultural change happened after the Prussian elites lost power and the general German public understood their recent history as far from the eternal victory they were promised.
But the "Prussian elites lost power" because of the rise of the National Socialists who are universally not considered pacifist.
It might be a "major cultural change" but it was not affected by people staying at home and changing things for the better.
The Prussians nobles were a big reason why the Nazis rose to power and were well integrated to the party and the army.
The Prussians losing power is not the reason why Germany changed, but because Germany changed its values (militarism wasn't sacred anymore) the Prussians lost power post-war.
That change was a change in the collective opinions of the entire country, and that did not happen because the allies took everyone to school but because people saw the effect of that ideology and the disaster with their own eyes, and their decision was not the same decision they collectively reached post-WW1