Microsoft Teams: Private channels increased limits and transition to group compliance

We are updating private channels to use a shared mailbox, similar to shared channels, instead of messages being stored in each user's mailbox. With this change, compliance policies set for the team's Microsoft 365 group will apply to private channels messages going forward. In addition, teams will support more than 30 private channels, up to the 1000 total channel limit for the team. Private channel member limits will increase from 250 to 5000. You will also be able to schedule meetings in private channels.