It's very short. Worth a quick read and a long thought.
People have been trying to talk to animals for thousands (tens of thousands?) of years, and no "animal myths" were discovered. Some researchers have dedicated their live trying to understand the animals (story mentions one of them), but still got nothing useful. I think it's fair to assume there is nothing to find there at all.
And alien life is not special in that regard - if we are able to successfully contact aliens, and then many thousands of people spend a century or two interchanging the messages with them, and all this would yield same artifacts that most Earth's 5-year-old kids can produce... then people would lose interest in aliens as well, and stop building things like Arecibo.
It's a good thing people who accomplish great things don't think like that or we'd have no science at all, because for millions of years we didn't. If they did, they would have had to conclude it isn't possible to predict the future. Yet here we are, knowing why apples fall (or whatever.)
It's important to tell former from latter. Unexplored things are not the same as things that have been explored and found false.
I took "reasoned to be false" as sort of a weak and refutable statement.
I think if your 4-year-old aliens were found, many humans would find them charming and fun pen pals (assuming they're not dangerous).
It would be useful as the fly by of Pluto, where we finally found out things we couldn't possibly have known looking from here.