The premise doesn’t even make sense, the tree of knowledge is a Bad Thing in the Genesis story. Even if it was a magic mushroom, how could you possibly come to the conclusion that it’s being depicted in a positive light?
Not at all. I'm certain that it differs between faiths, but in mine (Judaism), the tree of knowledge was not A Bad Thing.
Eating the forbidden fruit / fruit of knowledge exposed Adam and Eve to evil things; tarnishing their purity. After they ate the fruit, they awakened. They desired to wear clothes, possess things, have children, etc.
What we learn from this is that knowledge is not good or bad; it's how we use it that makes the difference. And from the standpoint of an "awakening" and mystical experience, the connection to psilocybin deserves further study.
The esoteric meanings were often mirror images of the exoteric (or plain/obvious/surface) meanings. So where eating of the Tree of Knowledge might be viewed as "bad" in the exoteric interpretation, in the esoteric interpretation it could be viewed as good.
Similar inversions happen with the snake in the Garden of Eden, who is similarly viewed in a negative light in the exoteric interpretation, but as good in the esoteric interpretation. The same thing happens with Judas, and even the creator God himself.
I'd encourage reading up on the Gnostics for more details on exactly what those views were.
So while the article mixes up which storied tree that image is supposed to represent, there's a real question of whether or not the similarities to the amanita mushroom were intentional or not. When placed in the context of esoteric traditions, it's a worthwhile question.
And, anyway, one need not be a gnostic in order to believe there is a hidden side to Christianity.
Plus, there are several translations of it. The common rendition into English is 'happy fault', which may be too positive. The other translations include 'lucky mistake', 'happy mistake', blessed fall, etc. Note again the duality, the paradox, and that the fundamental noun (fault, mistake, fall) is negative. It's a paradox, a mystery, meant to get you to think deeper, not some stunning endorsement of listening to Satan.