A very big question: How did Aaron find out about Yarebin's death?
Russia's attitude toward Yarebin is quite significant, and Yang Yi understands this well.
The reason is actually simple—a country's attitude toward its heroes determines its future. Yarebin was an unsung hero; he could never be someone widely known. But the KGB knows what Yarebin accomplished, and what he once did for the Soviet Union.
The Soviet Union is gone, but Russia's stance remains important.
If Russia hopes to restore the glory of the Soviet era, they must treat Yarebin with the respect he deserves. If Russia wants to completely abandon everything associated with the Soviet Union, they will handle Yarebin's case coldly.