Fox is just pulling out the long knives now so that they can at least pretend to be a serious news organization next year during the elections. Carlson’s ouster is a signal to their other mouth breather/populist hosts that none of them are more important than the news channel as a whole and that the opinions expressed are most likely all going to be coming from the top down in the future. The only crazy allowed will be that which has been previously vetted by Fox lawyers.
The accusation of a hostile workplace, the accusations of government involvement (ie, false flag) in January 6th, and the overwhelming likelihood of what was ‘underneath’ the endless Fox News redactions in the reams of Discovery that came out of the Dominion lawsuit all became too much for Murdoch to bear. I’m inclined to suspect that Carlson's stature with the network made him so full of himself that he felt indispensable and invulnerable and had no qualms about criticizing upper management. Maybe a memo came down putting everybody on a somewhat shorter leash in an attempt to keep them on the right side of the line between obnoxiousness and defamation, and Tucks stomped his foot and squealed “You can’t make me!”