This is true for the heptapods (at least in the story), who do not require causal explanation for their actions, but not for Louise, at least in the movie, as her perception of time does have actual (and very significant) consequences, which kind of defeat the entire idea and turn it into a time-travel story. Actually, in the movie this is also not true for the heptapods, who do have a time-traveling causal explanation for their actions (they do what they do because they will need humanity in the future).
You don't need to actually remember the future for you to view life as teleological. In fact, the teleological point of view is central to some human philosophies (of fate and predestination) without turning its believers into p-zombies (at least, not as far as we know). Fatalism doesn't require that you know the future for you to act. In fact, you may believe that the past offers cause, but you believe that it is just a perception, while the "true" (and possibly unknown) reason is teleological.
That "memetic virus" is no science fiction, and has been a part of human philosophy since forever. What is Oedipus Rex (429 BC) or even the bible (esp. in Genesis) if not a teleological view of life? And, of course, the story of Cassandra, who is cursed with the power of prophecy. There's also Macbeth, which is a little different as knowledge of the future is what sets things in motion. I personally found Chiang's story to be a rather poor treatment of the subject compared to other, older and better known ones, and the movie, while better executed, destroyed the story's philosophical point, however simplistic in its treatment.
In any event, teleology provides a narrative for millions of believers to this day, and you don't need to know the future in order to be a fatalist.