The question there is how accurate the US bombing actually would have been. The best target might have been the landing beaches with the congested beach and ships at anchor. At Gudacannal and New Guinea many supply convoys and troops landings were disrupted by timely airstrikes. Another question is if the B17s could have raided Japan from Luzon? MacAurthur apprently thought so. He made some 1941 statements about burning Japans cities to the ground with the heavy bombers. While decisive destruction was not possible what would have been the consequences if a squadron had dropped a few hundred bombs on some southern Japanese industrial cities in Dcember 1941?