I don't see anybody challenging OKC, not even Denver who has the best chance imo.
They miss Fred no doubt but even without him they still got the best rated offense in the league. Sengun is running the offense more which wouldn't have happened with Fred playing. Reed Sheppard has also been a pleasant surprise latey, who everyone said needed to step up in Fred's absence.
Chicago is going to surprise everyone like the Pacers did last season. They have a similar makeup with a bunch of guards that can score & Giddey is playing at an elite level as pg.