Exactly
It's likely to happen, and quite possibly what we're seeing is the Right's campaign to preemptively (try to) discredit a truth commission or a prosecution.
I'd theorize that Sanchez's confidence is based on reports by some of those involved at Abu Ghraib that the abuse was ultimately instigated by the CIA; that, in other words, culpability doesn't go up the chain of command, but laterally.
Of course, all chains of command stop at the White House. There is no direction that an investigation can take that doesn't end up there. The Right's fear is quite understandable.