Radical transparency doesn't mean you get to say negative things!
"The company is deceiving people and should reconsider messaging to reflect reality" is not a personal attack; even in a "blameless" culture, you are expected to note that the causal chain includes "Dave hit the wrong button, which should not have happened because we should have safeguards on the button and reviews to make sure we have safeguards on all the expensive/dangerous buttons." Sorry, Dave.
I say that as a manager of narcissistic assholes who are always “brutally honest” and feel that their honesty excuses their brutality.