Well, that's the way it's supposed to be interpreted anyway... but as with many things in politics, a careful examination may reveal a different version of the truth than what the headlines are designed to lead you to believe.
First, let's note that Brennan, for whatever nobility may be in the stance, isn't taking this stance because he thinks torture is fundamentally wrong, and/or he wouldn't authorize it again in the abstract. His quote, specifically:
"I will not agree to carry out some of these tactics and techniques I've heard bandied about because this institution needs to endure," Brennan said.See what he really said there? To paraphrase, he said, "I know that if we keep torturing people, eventually the US will be dragged in front of some international court for gross violations of treaties and such, and the CIA will be made the scapegoat, as they were before. I think the survival of the CIA is more important than any specific intelligence goal or presidential mandate." This is somewhat comforting, in an "ends justifying the means" sort of way, but less so in a "institutional survival should not trump the interests of the country" sort of way. But not to worry, because...
The director of the CIA is appointed by the president anyway, so if Brennan is uncomfortable authorizing torturing people, the president could simply find someone else who is less so. The political sphere has no shortage of psychopaths, as with the business executive world, and Trump is now in the Venn Diagram overlap. Brennan is free to take his stand, knowing full well that it wouldn't impact presidential policy, and he can still come out looking like the good guy if Trump prevails.
Moreover, Trump wouldn't even necessarily have to advise Brennan on what he was ordering. Remember, the statement was that Brennan wouldn't "agree" to using torture, not that he wouldn't agree to look the other way. In a world of compartmentalized information by-design, it would be easy for the president to co-opt part of the CIA to do black ops work, and/or part of any number of other semi-acknowledged paramilitary government organizations. The fact that Brennan professes to refuse to publicly rubber-stamp such is much more about cover for the CIA than affecting government actions.
So, credit where due: Brennan refusing to actively participate in torture, even if that means defiance of presidential order, is unequivocally a good thing. Nominally, it's what our military is already supposed to do (ie: duty to disobey order which is illegal), but having failed to do so in the past, an affirmation of intent to do so in the future isn't bad. However, I wouldn't take a victory lap for regaining the moral high-ground or anything: we still have a presidential front-runner who wants to conduct even worse torture than the CIA did previously, and the objections of one person in the CIA isn't going to impede that much. Props to Brennan, although at best, it's still a somewhat hollow victory for humanity.