New enhancements in Private Channels in Microsoft Teams unlock their full potential

Hi, thank you for all the comments. Sharing some responses here while I try to get individual responses working.

1. This change helps us lay the foundation for bringing newer functionality into private channels. The new features that are outlined in this blog will follow after the migration window is complete and we will follow on with enabling the app support in channels, that is a known request.
2. Specific to a question below on Purview retention policy, after migration of a channel, the policy scoped to Teams channel messages will automatically begin applying to the private channels as well.
3. Specific to a question below on DLP, please ensure that your policy set includes the group mailbox associated with the team that the channel is in to be included into that policy. 
4. Chet Patel - we'd love to partner with you on early access to the feature. Please reach out to me on Teams at: cduggirala@microsoft.com.