Recover a deleted team or channel in Teams
Recover a deleted team
It will be necessary for you to ask your IT administrator for assistance in recovering the deleted team. The blog post below can be used as a reference for them.
Recover a deleted channel
Go to the More options option and select the team name that you would like to manage and click the Manage team button to begin managing the team. Find the channel in the Deleted section on the Channels tab, and click the Restore button when you see the channel listed there.
As a result, every channel conversation, file, and tab will be restored after the upgrade.