I say 33%. I think it breaks down into thirds: 34% chance he stays in OKC, 33% chance he moves East to Boston, 33% chance he moves somewhere else.
We're just outright the best situation for him if he changes teams. We have flexibility, the easier conference/road to the Finals, bright present/future, max cap space, great coaching/management/ownership, etc. We're also tailor-made to beat the Warriors, and we've played them the toughest in the league the last two years.
We'll ultimately have to make a trade or signing before he commits, or at least convince him that we'll upgrade the talent alongside him, but if he does leave OKC, then I think we top the list of suitors for sure.