I think you're taking it in a different direction than I meant. It's not about massaging anyone. Information can only be acted on to effect change if it's delivered with the context to do so.
I've been in similar situations. The fallacy is thinking that "truth bombs" are an effective communication style. If you want to effect change you need to do some social engineering and politicking. Hate it all you want, but the human psyche isn't a technical problem to solve with data and figures. What you do is manage expectations and present ideas that let people walk out of the meeting feeling like there's some direction that can be taken without disaster. Otherwise you're Chicken Little.
Good management responds to bad situations by negotiating scope and translating delays into milestones that are achievable. Like the story makes ICs feel like heroes for dropping truth bombs and quitting before seeing anything change, then seeming to be proven correct is an example of that. In my opinion they failed at the task given to them, which was to analyze the state of the project and implicitly give management something to do about it.
And that was a lesson I learned early in my career, being tasked with analyzing the state of a project and assessing why it was shit. The mistake was concluding that it was shit, because someone got fired afterwards who could have actually done a good job. What I didn't do was deliver information in a context that could have translated into change. The same is true of the ICs in the story. This is bragging about failure.