John wanted to have his wife murdered. He looked for someone and found a person who could do it, his name was Paul. John explained how Paul would have to do it, and then answered a question asked by Paul. His answer was "she will be dead, she is not going to speak"
This story is based on a Hitchcok's film "Dial M for murder".
My question is why did John use the "going to" form. Is it because it is an evidence (as "look there are some clouds, it is going to rain") or an intention but when you are dead you have no intention or because it has been planned before.
Could "going to" be replaced by "will"?