"It’s certainly possible that the colleges were not being truthful’
I do think there’s amount of misleading going on, even if it’s an anonymous survey. However It’s more likely that adcoms think they’re being need blind when they’re not. The factors that UCB noted that favor high-SES students is probably an implicit bias, so adcoms accept kids in wealthy zip codes think wealth of the family had nothing to do with it.
However, even Harvard has a budget and most if not all colleges would like a certain amount of the class to fund others, and then come in with some FA. I’m going to guess the best have of a certain percentage of the class subsidize the others.