After the Finals Kawhi was confident to get the extension, you know he said "I'm sure they -the Spurs and his agent- will come out with a great understanding and a deal", but maybe the ball is on Spurs side of court more than Leonard's camp. The Spurs need have cap space next summer to replace Tim/Manu, so they may not be willing to give him the extension (despite what he wants).
IMO if they don't extend him this summer the risk of losing him for nothing in free agency next years could be huge.
It's hard to imagine he accepting his qualifying offer next summer and wait until 2016 to hit the market as UFA, but the new TV deal, Lakers with their deep pockets could lure him to his Cali home, and -you're right- a team without Pop coaching...there are a lot of things Leonard's camp should take into account.