If you were the UFC why would you make the match on Cyborg's terms though? Sure, they could pay big money to both Ronda and Cyborg to fight at 140 or 145. But what for? Cyborg wins, even at 145, and now Ronda is no longer invincible. The aura is broken, weight class explanations or not. You can't unring that bell. So now they have a tarnished champion and some 145 pound superbeast that stole her thunder, and the UFC doesn't even have that weight class. It would just be stupid business.