What do annihilationalists make of Matthew 26:24 (and Mark 14:21)?

According to the tag:

Annihilationism is the belief that the final judgement will result in unsaved souls being completely destroyed in hell rather than being subjected to eternal torment.

but it doesn't say anything about when salvation occurs.

This question assumes that if one isn't saved in this life, they will never be saved. The problem with that assumption is that it condemns the vast majority of mankind, which never had any opportunity at salvation. (This of course is a much more serious problem for non-annihilationists.)

But the Bible tells of a second resurrection, at the end of the Millennium, when all those that haven't been given an opportunity at salvation will be given their first chance. They will be physically resurrected into the Kingdom of God here on Earth and taught God's truth by those that have already been saved and converted into spirit beings.

At the end of this period, the very few remaining people that still refuse to accept God's way will be judged and annihilated.

Since he was destined to play a role in God's plan, it's not unreasonable to believe that Judas never was offered salvation. If so, Judas too will be bodily resurrected on Earth.

Given that he felt so bad about what he had done that he killed himself, we can only imagine how awful he will initially feel when he learns the truth. But that means that he will understand God's plan, will understand the importance of the role he played in it, and almost certainly will accept and receive salvation.

In the scriptures quoted in the Question, Jesus isn't condemning Judas, he is feeling pity for him.

And his suicide avoided decades of unnecessary self-loathing. From his perspective, his resurrection would have occurred in the blink of an eye following his death.

See also my answers to:

• luke - Is the thief on the cross the first person saved under the new covenant?
• What is an overview of Christian viewpoints on the eternal destiny of individuals who die never hearing the Gospel?
• What is the Order of the Resurrection of the Dead?
• Why did Jesus raise people from the dead, when they would have been in heaven?
• How do Christians justify lack of God's intervention during events where neonates get killed?

I believe Jesus said this while Judas was still alive. If a fetus is a person with a soul, than Jesus is not speaking about it being better that Judas never existed. Rather, Jesus is making a reference to Judas’ state of heavy remorse in this life to the point of suicide. We really don’t know about Judas’ state following death. Some read Matthew 19:27-28 as indicating Judas may even have a place in judging the 12 tribes. Perhaps Judas had a spark of saving faith to turn to God at the nanosecond of his suicide? We just don’t know.

Judas, when returning the blood money admitted, "I have sinned by betraying innocent blood.” The thoughts racing through Judas' mind of what he'd done, with no way to reverse it, and for having given up his chance at the GIFT of eternal life (it's a gift that God gives only to the saved [Romans 6:23] without which you will perish [be destroyed, both body and soul - Matthew 10:28) led Judas to kill himself. The horror Judas would have felt for having not attained the salvation he'd constantly heard Jesus speak of, Jesus, his Savior who said He'd personally chosen Judas to be His disciple, having his discipleship utterly lost thanks to the horrible sin of betraying his Savior, was simply too much for Judas. He knew he was facing eternal fire. That's right. Eternal fire. And the example that Jude sets forth, to let us know exactly what is meant by suffering the fate of "eternal fire" was to say that "eternal fire" is what Sodom and Gomorrah had suffered. (Jude 7) Please note. Sodom and Gomorrah are not still burning. That fire burned up every sinner in Sodom and Gomorrah. Was that fire unquenchable? Yes. It was ordained of God so that no one could have snuffed it out before it had completed its task. Is Jude's example of "eternal fire" supported by the scriptures? Yes. (Malachi 4:1) “Surely the day is coming; it will burn like a furnace. All the arrogant and every evildoer..." (including Judas) "...will be stubble, and the day that is coming will set them on fire,” says the LORD Almighty. 'Not a root or a branch will be left to them." In replacing Judas, Peter said it was written of Judas, (Psalm 109:8) "May another take his position". If we read further to 109:15 it adds, "blot out their name from the earth" Peter also quotes Psalm 65:25, "May his place be deserted" and a few verses later in 65:29 it adds, "May they be blotted out of the book of life". When you blot out a name from a book, it totally disappears. But when the book your name disappears from is the Book of Life, the sinner disappears as well, left neither root nor branch, as clearly stated in Malachi, as quoted above. It does not take having a god who would allow our lost loved ones to suffer and writhe in pain for eternity, to explain Jesus' comment that it would have been better had Judas never been born. Judas, being one of the 12 was destined to have the extreme honor of being one of the 12 sitting on thrones who would be judging the 12 tribes of Israel. (Matthew 19:28) Judas suffered extreme loss, horrible guilt and shame. He lost his savior and therefore he forfeited the gift offered to him of eternal life. His destiny went from one of righteousness and glory to being burned up like trash in a raging fire, which is the second death, from which there will be no return. (Revelation 20:15) "The lake of fire is the second death. Anyone whose name was not found written in the book of life was thrown into the lake of fire." Will they be "tormented day and night forever and ever"? Yes. But after Jesus returns, there will no longer exist any cycle of day and night. Night is no more and the sun is no longer needed. Jesus will be our light. (Revelation 20:10) Therefore there can be no more torment in hellfire past that point. When there is no more "day and night", there can be no more suffering "day and night". This is supported in Revelation 21:4 - "and He will wipe away every tear from their eyes, and there will no longer be death; there will no longer be sorrow and anguish or crying, or pain; for the former order of things..." (such as the cycle of day and night) "...has passed away.” There cannot be lost souls, therefore, endlessly suffering in hell if "there will no longer be sorrow and anguish or crying or pain". I believe this utterly hopeless situation for Judas who knew he was facing that fire and his utter annihilation, goes very far in explaining Jesus' statement, that it would have been better had Judas never been born.

As an annihilationist: while it is true that in the end, a sinner will not exist in any meaningful sense, there is still judgment day to consider. Imagine standing before billions of people, everyone who has ever been born, as it is declared that you betrayed God's son to His death. After this judgment, you are then destroyed, a process which most likely will not be painless. Thus we're not comparing two basically similar forms of non-existence, we're comparing A) never having existed in the first place to B) existing then committing and being judged for what is possibly the single greatest sin in the history of the world, followed by a (probably painful) death by hellfire. As Jess says in her answer, even while Judas was still alive he felt guilt and anguish so strong he killed himself.