Honestly everyone will move up their ranking if they win. What kind of question is this? Now if you're talking about who will move up the most then it will likely be a player that's underrated and disrespected. So likely someone that's seen as a wannabe star 2nd or 3rd option. That would be easily Pascal Siakam for me especially with the performance he put up. It would be his 2nd deep playoff run where he was a top 3 contributor to his team.
In terms of all time legacy if OKC wins and Shai has a good performance it will solidify his perfect season at a relatively young age still at the forefront of his prime. This is the most likely option and OKC may not be done winning. They have the chance at winning the championship the next 3 years providing there's no serious injuries and management makes the right moves with all the pieces they have.