Hi, @ylluminate
You are right on the fact that the mattermost channel move performs that check based on the documentation even for mmctl as well:
The command validates that all users in the channel belong to the target team
Is there any particular reason to override the check? At the back of my head, I would think that the feature is there to prevent messages from being lost when 1 or more of the account doesn’t exist in the target team, which could lead to audit / security concerns.