Barring major injury Giannis and Davis seem pretty likely after that I think there are any number of players that could be in that discussion with Leonard being the most likely to me. Simmons, Embiid, Porzingis, Jokic, and Towns are probably the next group, though maybe Durant, Curry, and Harden are still sticking around at that level. Then you have the young guys like Tatum, Ayton, etc. whose development could put them at that level.