It totally depends on the context. 数々の試練と戦いを経て成長して行くナルトたち can be used also for the case that thier growth doesn't start yet. これからも or この先(は) can be the indicater for each cases, "it already started in the past" or "it will start in the future", respectively. However, this would be from an explanation of the story, so it seems to be used with "flashback" images to me.