One of the most top-requested features for Microsoft Teams is the different kind of Channels that exist in slack:
- Public-Open (visible anywhere including outside the org and anyone can join)
- Public-Invitation (visible anywhere including outside the org, must be invited)
- Company-Open (only visible inside the org and anyone in the org can join; outside the org must be invited)
- Company-Invitation (only visible inside the org, must be invited)
- Secret (invisible to everyone except existing members, must be invited)
Microsoft just posted this on the Uservoice regarding this:
Its been a while since my last update, so wanted to check in and let you know that this is well under way. We’re aiming for early next calendar year (2018) if development and testing go well. I’ll ping you again with a more exact ETA after the new year.
In the organisations I've been to this has been one of the most requested features and one reason people keep Slack. Good job Microsoft!