In some cases, this happens because they don't have any information to share. It can also mean, though, that they have information that they fear may cause a panic among the staff. People can also be reluctant to speculate, as they don't like to admit that they have no information about what is going on. You may find that higher level management is keeping lower level management in the dark. One sure sign of trouble is when everyone in management assures you there will be no major changes and it is just business as usual.
Mergers are never business as usual.
If the merging companies are traded publicly you can obtain a wide variety of information from the SEC reports they are required to file each quarter. This will show you mainly financial data, though. There are many Internet sources that can search for information about the merging companies and automatically send you a report each day. Loyalty Loyalty has its place in all aspects of our lives, including business. I will say, though, that there is very little glory in going down with your ship.