The point of the thread is to have 3D technology apply to the game, which would allow rockets to fly out of the screen at your face. If we could see legions in 4D, then we could see all the jet-lines for the entire game and all the jetlines that would be. Computers aren't THAT good at predicting the future, yet.
Actually we don't see the world in 3D anyway, we see it in 2D with parallax (or if you want to get mathematical you can check out projective geometry which is how all rendering libraries work). If we were to see in 3D we would see all points as they actually are, not projected onto our retina to form two 2D images where we can gauge distance (with plenty of limitations). For instance if you're looking at a sphere each eye will see a disc and combined with a little hard wired trigonometry we can estimate the distance. If we viewed the world in 3D we would see the entirety of the sphere as a sphere, not as a disc. To see in 3D we would actually have to be bumped up another dimension (see Flatland).
Now your 4D example is actually off. You're treating time as a spatial dimension which it is not (see relativity). If time were a spatial dimension, then you'd see the entirety of the map from the beginning to the end. Of course it would be choppy and discrete since the game is updated at a specific tick rate. So it would look like frames of a video, only you'd see all frames at once.
Also, I will never wear goggles to view a parallaxed image, I will wait for autostereoscopic monitors to become cheaply available along with the rendering technology to take advantage of it.