Indeed. There is missing representation in conversations here that make those absences conspicuous. You can see a similar effect on, for example, a company Slac

Indeed. There is missing representation in conversations here that make those absences conspicuous. You can see a similar effect on, for example, a company Slack channel, and figure out which groups of employees are having the same conversation on a private channel. Nothing wrong with it unless the members of the side group are obliged to participate in general conversation, and they aren’t here.