Well psychedelics and festivals are definitely a thing, as far as a festival being directly called a "psychedelic festival" would be quite bold. But people have taken psychedelics at music festivals for decades.
Maybe, I mean, they already are pretty popular, and even accepted amongst the majority of society, but it's the government that will hold something like a "Psychedelic Festival" back. Idk, I wish you luck!
You could do some outbound to a lot of event organisers and see what their response is - Also a lot of booking sites are ranking high with this search term, so you could do some outreach to them or on the ones on page page 2 or 3 and see how you get on - has some monetary value, just not sure what it would be, check out CPC and other metrics and go from there....maybe?