My view is, have as many 1-on-1 conversations as possible during this time!
If you are exposing some staff (Managers?) to the acquisition, successful companies describe some of anticipated challenges that managerment might fact in order to come with a name.
Light information, to help the acquiring / acquired orgs understand each other, should be the focus of this planning.
If this is done with Managers in the right way, it can secure their support and buy-in for the merger during the acquisition process, which is time when many organisations need their Management to be fully supportive.