It is a possiblity. But I even have other perspective, Rather than sacrifice/murder sulli could be tired both mentally and physically of the mk ultra shit and decided to end her life.
I believe once you're a mk ultra slave it is hard to get out and I believe that if you try to speak out the truth they blackmail you and your family/friends.
The saddest thing is that nobody believes it is real and we can't stop it because this thing rules the entertaiment world. In the usa is already hard to prove and it has so many examples like marilyn monroe,kanye west,michael jackson etc, imagine in kpop that is a "new" genre and probably starting their illuminati agenda now.
It is impossible to stop them, unfortunately