My websites were always targeted primarily for the hardcore fans who almost know it all. The purpose of my sites was too shine light on some very obscure interviews and facts that aren't accessible in well known books or extras that are still available for purchase. However, times change, and new generations and fans come along - and I realized that a lot of my audience consist of fans who aren't diehards who know every book and interview by memory for decades (like all the fans at the Terminator Files Forum years ago), or just never went outside the films. So this is part of a different type of FAQ section, for those less initiated in Cameronverse. James Cameron is one of those very few storytellers who leave the fans with more answers than any scifi fan would hope for, certainly much more than any other scifi storyteller. While movies are about the kinetic energy, emotions visual art and story, and they are certainly not obligated to explain or elaborate on every fictional aspect of it, Cameron, often praising the audiences as 'smart' and ones who 'get it', spread just enough clues and sprinkled bits of information that are enough for the viewers to draw they answers from, without a need to do it through dialogue, ruining the flow, pace and running time of the film. And he always goes extra miles unlike anyone else to give reason and logic behind everything, even fictional made up tech.
Novelizations used to be for fans who wanted that extra insight into the story, unburdened by the limited running time of a movie and it's pacing - they dwelled on character's thoughts and explained things that couldn't be visually or weren't absolutely necessary or crucial to explain in the film, and so they're often almost like the Bible of the film, along the script. Let me underline that none of the answers are my own opinions, they are an intent of the filmmakers and official sources will be quoted when necessary. And have in mind, this entire site is just about Cameronverse only.
Let's continue with "What If Terminator Completes Its Mission?"
In Terminator 2: Judgment Day, we see the T-800 making a decision to sacrifice himself in order to ensure Skynet will never exist. He did that after his mission was complete, however, he is an anomaly as he is the first and only reprogrammed Terminator, so same rules do not apply to him as they would to "regular" Terminators. Not only that, but his experiences with John and Sarah taught him how to care for someone, and his decision to sacrifice was his most human one.
James Cameron in Starburst #159, 1991
But what would, for example, the first Terminator do if he completed his mission? The answer is in the US 1985 novelization. He would await the rise of Skynet and then await to be reprogrammed.
That itself also give a clue that Terminators did not have secondary programming or couldn't have one. It specifically says he couldn't do anything until he was programmed with new mission.
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