If you've ever worked in an environment where top brass assumed that they could impose changes on staff at will, and without rumors surfacing beforehand, you know just how clueless such leaders can be. It doesn't matter how tightly leaders try to keep a lid on sweeping changes because people always know when something is brewing. If leaders pretend that nobody knows what is afoot, then they won't communicate about proposed changes, and the rumors become progressively more outlandish. Then, when the change is finally put in place, the employees have already worked up a good bit of mistrust of the leadership. Employee motivation plummets.
Workers want to know what is going on. Have you ever been stuck on an airplane on the tarmac for long periods, with no communication from the crew or captain, and wondered what could possibly have gone wrong? If you're like most people, just learning the reason for the delay would be helpful because it would at least give the mind something specific to ponder: "Let's see, if we're number 47 in line for takeoff, and each takeoff is so many seconds after the last one ..." People are naturally curious about the reasons behind events and how those events will affect them. Leaders who try to keep things under wraps, and then spring a total paradigm shift onto the workforce are not effective leaders.
Leadership development requires acknowledging that people have questions and giving them as much information as possible in advance of changes that will affect their personal growth as an employee. If you are a leader, and those above you insist on evading rumors and ignoring employee feelings in advance of workplace changes, you owe it to those who report to you to find out the reasons why top brass is being so secretive. If leaders quash communication because "that's how we've always done it" or because they worry about what employees would do with any information, then they will breed mistrust as employees. When employees are denied concrete information, they speculate and come up with theories and rumors to fill the information void. Providing information is almost always better for making changes go smoothly. Employees will be more dedicated to their own professional development if they feel like they are part of the process, and not just pawns in games among company brass.