Given the timeframe and our current understanding of evolution on Equis, the scale only leads to further questioning and concerns. The oldest known ancestor of modern ponies and Saddle Arabian horses is perhaps only fifty thousand years old, if that, and ponies only began writing and recording history in ways we can understand since about eight to ten thousand years. If the humans depicted in the record were from a million years ago, are they still alive? If they are, their species has almost certainly evolved greatly from the time when the EEO was sent out, perhaps to a point where they could well be unrecognizable, even if their species was already around a hundred times longer ponies were. Any current possible humans may not even remember that this message was sent if documentation on it didn't survive. Given the technological level of just this million old EEO, current humans may not even be located in the same star system anymore, or even the same galaxy. After all, there are ponies obsessed with doomsday scenarios of giant asteroids hitting Equis (ignoring the fact that Princess Celestia and Princess Luna would likely be able to stop such a thing). If humans are as advanced as I think, and if they have no magical defenses, such a thing threatening to hit Earth may have led to a planet-wide evacuation to one of their local planets shown in the images — and that's if their technology hasn't advanced to the point where leaving their planet on a "space ship" of sorts isn't as common as ponies pulling carts.