Gobert was the 28th pick.
So let's say next season the Thunder get off to a great start and things are looking great. The problem is that Cam Payne is struggling as a rookie and the Thunder have issues with their backup PG position. Let's say Darren Collison, Aaron Brooks, Jameer Nelson, etc. is available and the Thunder are interested in upgrading. Typically a 1st rounder is a golden ticket to get a player like that, but I'm fairly certain OKC has their picks tied up until 2018 or something.
What I'm saying is I would prefer that flexibility and/or the chance at lucky pick over watching Dion chuck himself to his 5th consecutive sub replacement level season.
DJ Augestine is the very definition of backup PG.
Also, with KD back in the fold some of the secondary ball handling/playmaking responsbility is rightfully levied to him. With those three in hte fold its highly unlikely they are going to need to acquire a backup PG.