I doubt very much that is correct.

Germany's & Japan's populations suffered as little moral damage as the UK's did during the Blitz.

Germany's war-time production in general only suffered and faltered in late 1944.

Whether Germany had lost 0, 2, or 10 million civilians in May 45, massive Allied armies occupied the country and capital. As I see it, Germany primarily lost due to its lack of oil and battlefield defeats in the East.

Japan had lost the war economically far earlier than August 45. The scale of civilian casualties during the nuclear bombings had only a psychological effect on the Japanese government, although obviously a major one.