I bet we'll see more studies similar to that in the future, I know they did one with psilocybin within the past year
Terence Mckenna was always fascinating to me, I would definitely read some of his stuff. I don't really like Joe Rogan, he isn't as credible as a lot of people like to point out. He's alright, sure. Timothy Leary has some interesting literature as well. Fear and Loathing, The Electric Kool-Aid Test and The Doors of Perception go without saying.
I like what Joe Rogan has to say, I mean it is simply his opinion, unless he says "this is the truth" which I don't know if he does. When you look into stuff like this everyone sees things differently, it could be true to someone, whereas to someone else it could be completely false.