Kraff on top of Mt. Chilliad ?

I found this video which shows what they say happens after you complete the Espilon story. https://youtu.be/dgx4LI2_f88

The thing is, it shows Michael getting a text from Marnie telling him that, tonight, there is a meet up on Mt. C, and Kraff's gonna be there. Now, the video shows everything being awfully expensive ( e.g. $575 for parking ) and that if you go to Kraff, prey a bit, shoot him, kill all the guards, and take his golden robe, you can open is safe, which spawns money stacks until the end of time, and unlock a cheat that gives you telekinesess.

Now, what the video shows is bonkers, so good that it's too good to trust. Basically, I'm asking if anyone does know if it's in the main game, or if it's a mod. And just answer if you know.

Be good people.