If info goes into a monthly newsletter for all staff at a company, then management should either expect it to leak to the wider world, or someone in management is deeply naive.
The company I work for has monthly 'ask the CEO' town hall meetings. Because the CEO knows things will leak, he imparts very little information at those meetings; the result is that none of the rank-and-file staff go to those meetings because they know the CEO doesn't want things being leaked so doesn't say anything remotely sensitive