Don’t over-analyze this. Megyn Kelly is the future of Fox News. She will replace O’Reilly in that role and Fox will pay her whatever it takes.
This is just the normal Trump-like start of a negotiation for a new contract.
Funny how most people don’t seem to grasp that. CNN? Pfffft... they don’t have the money to lure her away. She’s not going anywhere unless some network offers her an anchor position or some prime time program.