I agree that there's a responsibility to disseminate harm reduction and inform people, but psychosis is still not the long-term adverse effect (even in the case study you linked). The long-term adverse effect for that patient was major depressive disorder.
If you're going to inform people, just make sure you're accurate. Use studies with better statistical power and a larger subject population, because case studies are literal anecdote - peer-reviewed anecdote, but still anecdote.
Here's a better analysis, as a fairly comprehensive literature review, that gives more detailed long-term adverse effects: Long-term effects of psychedelic drugs: A systematic review
Here are their conclusions:
Sustained changes in personality/attitudes, depression, spirituality, affect/mood, anxiety, wellbeing, substance use, meditative practices, and mindfulness were documented.
There are no mentions anywhere of persistent psychosis. At most, there are acute episodes while under the effects of the substance, and a very small risk of underlying mental illnesses like schizophrenia surfacing.
I apologize too if this seems pedantic; I'm a PhDc with a special interest in neuroscience and neuropharmacology, so these details are important.