"These will go away into eternal punishment, but the righteous into eternal life." (Matthew 25:46, New American Standard Bible, emphasis added)
"Cutting-off" as a word choice in Matthew 25:46 by the Watchtower Society is a clear example of them taking liberties with the text of Scripture to support their false doctrine of annihilation.
The text actually proves injurious to the Jehovah's Witnesses position because heaven and hell are paired side by side and described as eternal.
Moreover, the Greek kolasis is better translated as "punishment" than "cutting-off" because that word is consistent with the overall context of Scripture. Jude says that the cities of Sodom and Gomorrah suffer "eternal fire" (Jude 7) which lasts "forever" (Jude 13) as an object lesson for the ungodly. That language has very specific implications. It does not sit well with annihilationism.