Is "breaking the threat" a legitimate concept, meaning that Allah's threat of punishment might not be fulfilled, and does this contradict the verse "all denied" (Quran 67:18)?

Allah Almighty forgives sins, even the major ones, except for shirk (definition) (associating partners with Allah) and kufr (disbelief), as stated in His words: "Indeed, Allah does not forgive association with Him, but He forgives what is less than that for whom He wills." The threat (wa'id) in His saying: "Each denied the messengers, so My threat was fulfilled," cannot be averted because it applies to the people of disbelief. The threat is not averted if it is for disbelievers, because their denial of the messengers is the cause for the inevitability of punishment. What confirms this is His saying: "The Word will not be changed with Me, and never will I be unjust to the servants." As for the threat of punishment for disobedient Muslims due to major sins, it is permissible for it to be averted, as it is an act of forgiveness from Allah for the sins of His disobedient believing servants.