Agree with your overall point, but a "revealed preference" isn't necessarily a lie or lake of self-knowledge. A recovering alcoholic might have a revealed preference for alcohol but that doesn't mean they're lying when they say they don't want it or that they're unaware of the temptation they have for it (insane as this may sound, people have actually made this argument before). The whole economic concept rests on massive philosophical and psychological cans of worms about what defines a person's identity and wants, which economists are happy to oversimplify and ignore. The average person can't really be expected to track entire supply chains for every purchase they ever make, which is why we have regulations. Instead of having every individual track every part of the production of every purchase, we (as a society) assign someone the job of investigating the production process to see if there's anything that we would find objectionable.

If a lot of people say that they have a problem with sweatshops, but then purchase goods made in sweatshops, you could argue that their behavior "reveals" their true preference, but it would be equally valid to say that what what they actually consciously express is their true preference and their failure to live up to it is driven by ignorance, succumbing to temptation, or regulatory failure.