Yes, that is one view. And I've also heard the view that it wouldn't have come to that and that the Japanese were near surrender. I don't know which is nearer to the truth.Depends on what projection you believe. The Allies thought many more would die, civilians and military included, if they were forced to fight street to street and house to house to subdue the Japanese. They'd shown remarkable bravery and tenacity in that sort of situation.
Regardless, you would have to rely on speculation and I don't think I can justify dropping an atomic bomb on thousands of innocent people because I have a theory on what might happen if we don't.