Remember the beginning of T2? A dark road running into the distance; Sarah Connor’s voiceover speaking about the inevitable an impending future? The movie ends the same way but this time she’s talking about the openness of the future since things have changed. Instead of depression she’s speaking in hope.
Good thing Sarah Connor didn’t survive until Judgment Day. Sure things changed, but not by much. The machines still took over. Connor still wound up being a military leader. Her fears were realized, even if she wasn’t there to see it happen.
But she had hope because of change.