Right so you can see from the two Conor fights, Nate has been a multi-millionaire for nearly a decade. Nate then made many more millions in the Masvidal fight.
He is not going to sign to be under contract again, the dude has a promoters license and co-promoted the event with Jake. You don't need to make short sighted decisions for cash when you have a high net worth.
Conor was grossly, grossly underpaid by the UFC. He was getting pennies on the dollar. There is zero chance he resigns with the UFC unless they give him a radically different deal, and that is why he's been publicly commenting and tweeting about having a third fight with Nate. They will co-promote but get to keep all the value.
People like to hate on Nate because of his persona but he's a self made millionaire who advocated for himself and won. He's a savvy businessman.