This has been a recurring theme throughout my career, the struggle between being seen as "alarmist" and accurately conveying urgency.
We get this in the medical field all of the time. "Outcomes delivered via mechanism seen as potentially contraindicated" or some other spaghetti. I've been in these meetings many times, where we (the individual contributors) have to tell the bosses or peers or partner group about something that might be bad. As in Y2K-style of bad, where it will be bad if we don't address it but if we do address it with the urgency needed, no one will be able to recognize the success for what it is.
As you said, no one's manager wants to be seen as crying wolf all of the time, but post-hoc there's the expectation that a couple of engineers way out at the end of the limb of the tree didn't just wait for the limb to be sawed off behind them, they took out the saw and did it themselves. That they stood up in the presentation and yelled "you're all idiots! This is going to kill the entire crew! Everyone will die, don't you see?! And I'm not standing for it!" just before they rip the badge off of their lanyard or belt hook and then righteously storm out.