You can use the PG analogy, but I can also use the Boston Celtics/Gordon Hayward analogy. Pretty much everyone knew that Hayward was either re-signing in Utah or going to Boston for Brad Stevens. The Celtics didn't bother making that trade because they felt strongly enough they could just sign him in free agency. Obviously not 100% exact same situations, but very similar.
I don't even think PG reports were this public about him wanting to be in Los Angeles. Kawhi seems hell bent on going there.
Let's say you are right (and you very well could be; remains a gamble for the Lakers, but a gamble they very well could win).
The Lakers still have the pressure of making this trade ASAP. Lebron is no spring chicken and they don't know how long he will still be THE best. Sure, logically, it should be 2-3 more years, but who knows. If they want to win with Lebron, they need Kawhi.
Kawhi wants to go to LA and LA only, that gives the Lakers leverage.
Lakers have to make that trade to contend, that gives the Spurs leverage. That being said, even with Leonard, they likely won't win in 2018. Time for the team to gel, some of the young guys to gain experience, etc. So the Spurs' leverage isn't that great.
Spurs risk losing him for nothing, that gives Kawhi (and the Lakers if he REALLY only wants to go there meaning other teams won't be willing to make great offers for one year of KL) leverage.
As I said earlier, the only real winner in this situation in Kawhi himself. He holds the Spurs by the balls. Either they lose him for nothing, trade him for a less-than-ideal return to another team or have to comprimise with the Lakers. They are smart to gamble that Magic will panic and offer them the moon (as I said, he KNOWS he needs Kawhi to contend).
Very interesting situation.