Public/private is orthogonal to Slack/email. You can communicate by email in open DL/mailing-list style, and many default to using Slack with private group thre

Public/private is orthogonal to Slack/email. You can communicate by email in open DL/mailing-list style, and many default to using Slack with private group threads. I do strongly agree with the main premise that open is better than closed. This requires organizational cultural discipline to pull off; someone needs to be pushing and training for an open approach to be used by default. But you don’t need Slack to implement that open style.