More an analysis/conjecture, but besides potential propaganda within the Soviet Union and in the frontlines, information and counterinformation are part of a war, so the German Intelligence may have come across the information of that bomber regiment, which turned out to be true. And as gossip spreads like fire in dry vegetation and the German hierarchy afaik was purposefully messy, what the Intelligence would find could end up leaking to the front lines, and thus confirming the propaganda and rumors the soldiers could be hearing.