You can create a read-only discussion circle and adjust the settings so that only the managers can create posts in it. You can also disable the reflections on these posts.
Create a discussion circle.
Being inside the discussion circle click on the Manage button and select the Additional settings. (Read more about all the Additional settings).
Scroll down till the Message posting and choose the Read only option.
You can enable or disable the reflections in Reflection settings.
Make sure you invite your participants to this circle for them to be able to receive the updates via the email digest.