"Moreover, the enemy has begun to employ a new and most cruel bomb, the power of which to do damage is, indeed, incalculable, taking the toll of many innocent lives. Should we continue to fight, it would not only result in an ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization."Whether 1 bomb or 10,000 were used to delete a city made very little diference to the japanese.
Hirohito didn't even mention the conventional air raids directly in his surrender speech.
There's a class of historical revisionism which involves ignoring what was said by the original participants in favor of a preferred thesis.