The mind control experiments at McGill are mentioned as a foundation for Naomi Klein's "The Shock Doctrine" (a must read).

Whether cults surround the MKULTRA is anyone's guess but these experiments did take place there at McGill.

There is an interesting corollary, that of Scientology, John Travolta and Tom Cruise.
Hollywood is prone to this kind of cult, drugs abound, especially in the movie industry but whether there is a extensive coordinated effort to take over minds is kind of flimsy in that these incidents described seem sporadic.

I didn't know that Christopherson worked for the CIA. Is this really true?

I do know this. Drugs change the mind chemistry and weird things happen to people who get mixed up in them. I recommend Dave Crosby's book "Long Time Coming" as a background for the Hollywood pop scene centered around the Troubadour on Santa Monica Boulevard. He describes the drug scene in music very well. I encountered many people who fit the description of "alters" that were abusing LSD, one notable fine guitarist who was checked into Camarillo and came out with a shell like personality.

I attribute a lot of what happened in the Sixties and Seventies in the music scene to the control of the business side of recording through supplying access to drugs.
I was in Hollywood around the Seventies and saw a lot of stuff happening.

Cults are a Hollywood staple. The entertainment business is highly susceptible
to them.

I don't think that this story is as strange as it's painted. The commercial music business has it's weird side due to drug use.