Imagine going to a conference afterparty and being told by the host you can’t discuss key aspects of your work with fellow professionals.
If you’re like most people, you would step outside (or head to a bar down the street) and talk there.
This is the problem with creating a community and telling members they can’t talk about key topics.
For sure, you might not want members rambling on about their personal lives or swapping their favourite cat photos (unless you do). These discussions are outside of the common interests and should take place on social media. You also probably want to avoid legal landmines too.
But to restrict what people can talk about within the common interest is generally a really bad idea.
Create sub-groups for certain discussions if you like. Use your subtle influence to guide discussions in a certain direction. But be sure to push back against preventing members talking about things they want to discuss. This is a community killer.
These discussions help bond members, they give members a reason to repeatedly visit the community, they increase the likelihood that they will (perhaps eventually) talk about the topics that deliver the results you want.