It could be that they're saying you should artificially hold back part of the news to ease the shock, which I don't agree with. But there are situations where

It could be that they're saying you should artificially hold back part of the news to ease the shock, which I don't agree with. But there are situations where a problem unfolds gradually, the sort of thing where you become more and more aware and certain that something is going wrong. For example, when a schedule slips. It's possible they're talking about that kind of situation. In that kind of situation, there's some threshold where it gets bad enough to let people know. But you could also give people a warning some time before that, i.e. have an additional threshold and an additional earlier communication. So maybe the advice is to go ahead and do that additional communication.