A little late to the discussion, but here's my take on this "rumor" (use the word extremely loosely as I agree that it'd never happen in a million years.)
There are only 2 scenarios where the Blazers willingly make this trade, and as you'll see, both involve extremely unlikely circumstances AND are highly unlikely that Sacramento would also agree to them.
Agreeable Scenario #1: The Blazers would agree to this trade if they somehow KNEW, beyond ALL REASONABLE DOUBT that G.O.'s career will never be the same and that he is, in FACT, "injury prone". If you could somehow show me irrefutible PROOF that he'll never reach any sort of heights that we all hoped he'd achieve, then yes, they'd move on and take what they can get for him. This deal might not be the ideal time to "sell high" but under this scenario, it's probably not the worst offer we'd recieve either.
Problem #1: Why the hell would Sacto want busted goods in Greg?
Problem #2: Doctors are routinely baffled by people who wake up from multiple year comas after being thought to be "lost causes", paralyzed people, told they'll never walk again not only walk but some have even returned to competition. The body is a mystery that even at our top levels of science still does not fully understand. There is absolutely ZERO way that anyone could tell you, with 100% unyielding certainty (with the obvious exception of Greg being deciest) that he wouldn't be able to return to play acceptable basketball.
Agreeable Scenario #2: Sacto wins the lottery and still wants to trade Thompson and the pick for G.O.
In this scenario, the Blazers get John Wall, probably the most NBA ready talent (at a position of need noless) since Lebron, and who knows before him. Wall, like GO could very well be a crutial piece to title runs in our future. Additionally, his presence would make players like Bayless, Rudy, Miller, etc. more expendable, which means that we'd be able to use our depth and talent to return another big man -- one who hopefully WON'T be "injury prone".
Problem w/ this trade is that I still can't see how or why Sacto wouldn't want Wall. Seems like he and Ty Evans would work very well together in a backcourt.
Those are the absolutely ONLY ways I'd do this specific scenario. As I said, ain't gonna happen...