Everyone knew he was gone despite him saying he wanted to make a LW title run and fight Tony. He took the short notice fight cause he wanted to end his contract quick. His manager probably had a deal with PFL or Bellator before that fight even happened.
At this point his best days are def behind him, he's more top 15 gatekeeper than a contender, he's gonna want to be paid well and UFC is in process of letting a bunch of guys like that go.
The writing was on the wall.
He was sort of like Chandler in Bellator, fought everyone, been a company guy forever, been world champ and theres nothing more to do there. They leave for different reasons, Chandler still has more left in the tank than Pettis at this point and wants big fights to be the world champ and Pettis wants that big final payday.
Where he ends up will determine what kind of fights there are for him, PFL he could be a favorite at LW but the bigger fights are in Bellator. LW is wide open without Chandler and maybe they finally do something with that title instead of letting Patricio hold it for 2 years. He could fight Patricky, Jury or if he stays at WW you have MVP, Daley, Larkin. His brother is there and he's alot younger than Romero who they just signed so Bellator seems like the logical fit.