Polytheism, Monotheism, Atheism, and Space Aliens

What if, later this afternoon, an Intelligent alien race lands here on Earth and makes contact with us. What if they contact our leaders and after exchanging business cards, they ask "how advanced are you?"
We humans interpret this as we can and respond "currently we can control nuclear fission but not nuclear fusion."
"No, that's not what we mean," replies the Alien. "How advanced are you, as in are you polytheistic, monotheistic, or atheistic?"
We respond "the majority of humans are monotheistic."
"Oh, okay," replies the Alien. "See you in another 200 years."
"Wait, what?!" we ask.
"Well, you see," replies the Alien, "there are more than 2,000 Intelligent species in the Universe that we've cataloged so far, not including you 'humans'. And of them, all 2,000+ followed this exact same socio-developmental pattern: polytheism, monotheism, atheism. And it turns out, interestingly, that when an Intelligent species reaches a plurality of atheists, that milestone means they're usually socially, mentally, and emotionally ready to join the interstellar community."

The question I have is this: given this information, that 2,000 out of 2,000 Intelligent species had all followed our species current religious trend, and it had ended in planetary atheism...how many monotheists would drop religion?
My guess is many would, but not nearly all of them. More likely is that new membership would massively plummet, as the young hoped they'd get to join the interstellar community once they shed the suddenly-archaic-seeming belief systems of their elders. But many Muslims, Jews, and Christians would die believing that they were right, and 2,000+ Intelligent species of Aliens were wrong. Earth Exceptionalism.

The case can be flipped around. What if the Aliens arrived and reported that of these 2,000+ species of Intelligent star-explorers, pretty much all of them (except the cyborg race of Planet 95C2) had a strong monotheistic religion on their planets. The belief in One God wasn't just a plurality on Earth, it was literally Universal. How many atheists would take up a religion, in this case? I bet some would, but most would just argue that obviously Faith isn't just an Earth construct but rather a universal construct of Intelligence...all Intelligences in the Universe share this flaw.

My guess is this: it is much easier to strip monotheists of their beliefs than it is to convince atheists to believe.


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