Line workers, staff somehow know
While management tends to think that are keeping secrets on the health of their company, lineworkers and staff have their communication channels to the company scuttlebutt. The moral of the story is for management to keep it honest and above board.
In cases where management through diversion has been able to hide the health of the company and then announces a surprise layoff etc. they become the emperor who has no clothes underscoring the need to keep it honest and above board.