Parsons was a unique /strange situation, hou was holding out for bosh and had maybe a better player in their backpocket with ariza. I can't see why gsw would let barnes walk
He won't be a RFA if they can't get an extension, and MAYBE he decides he wants a bigger role, even if it's not worth it.
As for the KD stuff. I think it's possible, just unlikely. If he were to leave, I still think this is where he goes.
If we could somehow keep most of the contents of this roster and add another star/justified max guy before KD. Then I think the odds shoot up.