I found it more important to emphasize trust, and allow them to handle these conversations/attendance If they couldn't, that's fine. Outside factors can disrupt this, ... So I wouldn't complain if there was a no show once in a while.
We had a monthly tea(m)time to share tea and talk about anything, hobby topic or something technical. It was fun to see what people do with 3d printers, especially those that had no time/space for this.