Due to prioritization of other work-items this has been moved to the backlog. We will update when it is being actively worked on again.
I agree at least being able to export/import would be a great start.
Another way to maybe get around having to move channels is to allow more granular permissioning. I think people are used to other programs like Slack and Discord where permissions aren't limited to a "Team" but can be permissioned down at the "Channel" level.
I also like the idea of if you can move content to another channel then have it leave behind a link to where the content has been moved.
I totally agree with @mike tokue that people are going to setup their teams and channels wrong and want to move them. Then they will realize that they can't :(.
I also like the idea that @Mads Nissen said with moving content in a channel. A good example of this is an option for a moderator/admin to be able to click a chat/discussion and say, "Move" then it would prompt them for the reason and leave behind a link to where the conversation went.
Isn't this the Activity tab?