Typically the modeling for a view considered to start with picking the source tables/views involved with that view, in that case the default transformation is generated based on name matching. I do not see much value in providing the above request, not to mention gives a false status of view being "valid", where it is not. May be an option in the "Reconciler Window" to add that button would be good, when there is no good conversions are available. You can do this now, but you would have to manually enter null.
It happens often enough in the development cycle that I feel it a worth addition... Especially in context of a generated object from XSD or possibly WSDL would have the same purpose.. ANY time a "top-down" approach to modeling is being done I can see the value.. Maybe I'm in the minority but I know it's often that I have, through the iterative process of development, have a partially finished object that I need to do something like this (or delete it) before I can test other components within a VDB.
I am just advocating where this may fit in. You can log feature request in Teiid Designer, it is upto the Designer leads to give the priority to the issue.