Yes! This is what more CEOs of large companies need to do. If you are a CEO, you need to understand what is going on in the company first hand, not by playing whisper down the lane with the chain of command. (This is my philosophy, hopefully reality one day.)
He's going to get a very sanitized version of the experience. What would be really amazing is if he disguised himself and went to work in the warehouse unannounced. Although I'm sure there would be plenty of self righteous outrage if he actually did.
The important thing is that he is going to be at the same level as those employees. He can ask them questions such as, "What needs improvement?" He's a bright guy so I would imagine he can figure out a way to make the employees feel comfortable enough to be dead honest with him. While you are right that there will be some cleansing, in general the employees can show him what they are talking about in a way that some feedback form just couldn't accomplish. (I must note that even dishing out a feedback form to employees once or twice a year is a giant step for many companies.)
I am biased, but David Neeleman (JetBlue, now starting Azul) is an amazing CEO. Just a few days ago he was flying around Brazil on his new Azul airline anonymously to verify his employees are implementing the level of customer service he is hoping for.
Edit: Compare that to the Washington DC Metro Board of Directors who don't even ride the Metro Trains they are overpaid to "direct".
