The Terror has ended by October 1938, when Gagarin was 4 years old. I wouldn’t call that “living through”.
I’m not saying there weren’t political prisoners or executions later. There were, but the scale is incomparable. We can safely say Gagarin met a lot of people who had won the war growing up, but he had not seen someone familiar taken to prison for no reason every other day, and I would assume had not heard much about it.
I didn’t comment the letter, I commented your idea that he lived through the Terror and thus the letter. No, that wasn’t the case.
And once again: the terror the society experienced that was vivid to Gagarin was from the Germans and not from Stalin (although indeed it experienced both).
I don’t want to speak to the tone of the letter, you may interpret it as designed to do something and you may not. But to say that it is somehow influenced by the terror that happened before his time and not to someone in his family, the terror about which for all we know he knew nothing, and in society that had a major uniting experience since, is to put your thoughts in his head.
I’m not saying there weren’t political prisoners or executions later. There were, but the scale is incomparable. We can safely say Gagarin met a lot of people who had won the war growing up, but he had not seen someone familiar taken to prison for no reason every other day, and I would assume had not heard much about it.