You prefaced your hypothesis quite well, Vidiot, insofar as you are tentative in putting forward the supposition that evidence exists and concluded quite logically that the information age will pop the lid off the secret archives if the supposition is indeed true. But that in itself is a giant leap forward that requires at least partial suspension of disbelief in order to proceed with what follows.
Your reference to science fiction is revealing, particularly that you enjoy it so much. So do I. But enjoyment of science fiction requires the same facility as does enjoyment of Harry Potter or Lord of the Rings, and that is complete suspension of disbelief. Stephen Hawking refers to science fiction as "space westerns" because they require bending the laws of physics to the point of breaking them, in particular relativity theory. For there to be extraterrestrials, even as close as alpha centauri, space travel would require decades. The fact that alpha centauri is a binary star system makes the probability of life quite low, particularly life sophisticated enough for space travel. Then we get into the planetary anthropic principle and exceedingly remote odds of the kind of goldilocks zone situation that our planet has existing elsewhere in the galaxy. That does not mean it doesn't. Even if the odds are one in a billion that might mean 50 earth-like planets in the galaxy, but if so they will be statistically thousands of light years away from us, all but ruling out the possibility of space travel within the bounds of relativity theory. The third thing is SETI, which has so far failed to detect any confirmed transmission indicating intelligent life - assuming that transmission of information would be a necessary prerequisite to develop the science of space travel, this alone is a pretty good indication that sophisticated civilisations, if they exist, are very, very far away from us.
Now, all that aside, your conclusions about how contact would rock the world's religious systems seem rational. And Hawking, hedging somewhat on the improbability of contact, has said that if it should ever happen, the probability would be high that exploitation would be top of the extraterrestrial agenda.