What makes you think they'd want to get rid of him. MBS is precisely the kind of lunatics that the CIA used to go out and protect. MBS serves "National security interests".
That is holding lesser truth as we have come to see how cozier MBS has been getting with Putin and Xi while he's been giving the silent treatment to the current leader of the Saudis' biggest historical ally. That's definitely not serving US national security interests if anything.
Manuel Noriega used to be heavily supported by the CIA before his crimes became public knowledge. Then no one had to ask it twice for the CIA to turn their cannons back on Noriega. I hope the same will happen with MBS if he keeps on going like this.