I agree it could be a nice feature. However, it's not just documentation of behavior. It's also implementation concerns, and the introduction of bugs by swapping out the parent of a table configuration in the configuration hierarchy.
It's not an essential part of this feature. We can always add it later.
Besides, you can achieve the same effect, but with more well-defined behavior by cloning a table across namespaces. (It's more well-defined, because the new table will never inherit from the old configuration... only the new one, from the moment it comes online.)