Allow owner of a team hide a channel from rest of the members or drag channel into a different team.
Allow an owner of a team hide a channel once it is finshed.
My company has an "Advanced Program" Team; basically of all the preproduction parts. Within this team we have channels of all the different programs/customers to these parts. Once a program/customer has reached FULL production and isn't talked about in the weekly company meeting, we have no need to have the channel.
We do not want to delete the channel and lose all information. Nor can we drag that channel out of the "Advanced" team into the "Full Production" team.
Allow an Owner to hide the finished channel from all other members. OR. Allow a channel to be dragged from one team to an other team.
Create an static "Archive" (type team) at the bottom of the Teams list, allow dragging of channels to move a Channel to this archive group. Once the channel is moved into the archive group one could edit the channel and either revoke user permissions or leave it available for users to access as read-only. Allow to set an auto purge channel function after a duration of 30 days, 60 days, 1 year.. follow retention policies.