Teams administrator can't provide access to Private Channels
A Teams Private Channel has been created by a user that is no longer with the company, and the user account has been deleted from the directory. The Teams Administrator cannot make a new user the Owner of the Private Channel. Only an Owner of of the Private Channel can make someone an owner. If there are no Owners left of the Private Channel then we have no way of modifying membership.
Pat S. commented
Choose TEAMS --> manage TEAMS --> choose teams name site -- >private channel
Add a user and promote it Owner of the channel
We have the same issue, the administrator needs to be able to provide private channel access when there are no owners or members in the channel. We have data that is needed but can not be accessed as the only owner and member was kicked out when they chose an option in planner that resulted them in leaving the team and all channels.
Though this can be done in the admin center, Team owners need to be able to do that as well
As you can see in the image attached, it is only possible to delete a private channel or show the channel owners. I need to be able to appoint a new channel owner, as the Team owner.