San Antonio without Kawhi might be better in the long run. They've been good for so long that they lack a lot of young talent. If they could move him for some draft picks and young guys (even though he's young) they'd be all good.
But like you said, it's possible that outsiders are starting these rumors. If that's true then San Antonio will be a threat again next year.
Even 3 decent players can;t make up for the impact that Kawhi has on both ends of the floor. I'm near 100% certain that team are telling these reporters to put out these rumors.