"China's rulers reveal more than intended with clunky propaganda about their accountability." What does "more than intended with" mean here?
Through propaganda, a person either wants to portray themselves as good, or someone else as bad. These "rulers" would have intended to show the things that make them look good, but they revealed too much/the wrong things and therefore have portrayed themselves in a negative way.
They wanted to show that they're accountable (not corrupt), but the propaganda revealed them to be corrupt.
In a sense it's like reading between the lines. While they may not explicitly come out and say what the true intention is, with a little clarity in one's own mind, you could probably parse out what's truly going on here.