A few weeks back, June 26th specifically, Microsoft announced archival functionality for Teams.  Archiving a Team does just what you’d expect by keeping the Team itself, but freezing changes to preserve the current state of the data.  There are a couple of things that I found interesting, and good to know before you get started.

1. While a Team is archived, you are still able to add/remove members and update roles for those who need access.  This seems useful as someone new may join your project/department/workgroup and need access to this data contained within the Team.
2. Archiving a Team is not as intuitive as I expected, though.  I (incorrectly) assumed, the action to archive a Team would show up directly under the more options pane from the Team itself.  Instead, you find the ability to archive the Team under the “Manage” cog from within the Teams pane itself.  Once there, you will see both active and archived Teams as well as having the ability to archive an active Team.
3. Most importantly (to me anyway) is that archived Teams still follow Group expiration policies configured in Azure Active Directory!  This is important to be aware of because Team owners will still need to renew the Team before it expires.  I did not find this aspect documented by Microsoft anywhere but was confirmed by a Microsoft Teams Program Manager via Twitter.

4. Finally, it seems that archiving individual channels within a Team is on the horizon as well.  If that functionality is something you are interested in, be sure to vote it up on UserVoice.