Even if they faked his death I think they'd only dare to do so if they had evidence of what we've all suspected for a while anyway - that the man has been dead for years already. But instead of saying, "oh yeah, we found out that he died in some cave in 2007", they want to make a big propaganda event out of it, and say the US actually killed him to death themselves, as opposed to, I dunno, dysentery or something. I suppose that's kind of possible.
If there's any chance he's still alive it's simply too big of a gamble to lie.
I'm never much of a conspiracy believer anyway but I really do believe the guy is dead.