I think what helped most was Oladipo's development from 3 and having to play better off ball. I wouldn't say his solid year in OKC was a breakout because he had also shown flashes of being a good player during his time in Orlando. Also, Sabonis (a lottery pick) was also an important part of the trade and even then everyone thought the Thunder robbed the Pacers.

To me, Oladipo deserves most, if not all, the credit. Not so much playing alongside Westbrook on the court. How I interpreted Oladipo's comments (other than just having nice things to say about a likely great teammate) was that he probably learned a lot from watching Westbrook and being his teammate. But I don't think he improved because of his minutes on the court with Westbrook. Confusing sentence but I hope my sentiment came across decently.