If the events were in the recent future, then it is reasonable to assume that the person who printed the newspaper either had control over the events in question (not likely, but still possible) or else had sufficient knowledge to reach a conclusion.
If the events were far enough in the future to eliminate this possibility, then I would only arrive at the conclusion of time travel once the need to arrive at that conclusion had passed.
Which is to say that if I am handed a newspaper which supposedly is set a week in the future, and those events come true, then I can assume that the person who made that newspaper had some kind of insider information - most likely at whichever establishment produces the periodical. If there were accurately reprinted news stories and editorials, I would simply assume that the person who printed the first paper had access to email or documents, intercepted them, and printed them first.
But if I am handed a newspaper which is supposedly set two years in the future, then I won't know for sure until two years have passed - which makes this a deeply troublesome method for someone who is trying to accomplish a goal by convincing me of something.
If the goal is to convince me, and they do the above, then come back after I'm convinced, and need help THEN... well, this is a massive risk. Now I'm aware of the truth that they are time traveling. But who's to say that I agree with their goals? I may have just created an enemy. Or perhaps I'll engage in the all-too-familiar practice of DENIAL. If a time traveler is intending to change a human being's mind, they must accept a chance of failure.
Therefore this is a plan which requires THREE separate missions to the past: first to pick up the relevant newspapers, second to deliver them to a displaced position in the timeline, and third to rendezvous with the contact. This is a very resource-draining plan, considering that the potential benefit is ONE temporal native ally, the most likely outcome is "I still don't believe you", and there's always the possibility of creating an enemy.