I'm a dork for this kinda stuff. Don't let me shit on it for you. There is a good chance if you could travel at the speed of light and something is 1000 light years away, it may not exist anymore, leaving that aside, cool. I love sci--fi. Also, we are literally absorbing light through the rods and cones in our eyes and I'm reading and what you're writing from possibly a country away, so it's not entirely far fetched. If there were a being with this capacity, why travel at all? Time is such an abstract and uniquely human property. Both important and unimportant, when moving through physical space. DMT removes the constraints of time and allows you to travel all the same.
Discussion
The travel would be necessary or you wouldn’t be able to accelerate through the light and get closer and closer to present day. Staring from simply 1000 years away doesn’t tell you much.. yes, I’m sure many of those civilizations would be extinguished upon arrival. But if these beings move in a way we can’t understand, virtually instantaneous, that wouldn’t matter to them. They are simply collecting data.