Not suggesting we take all existing money out of circulation, just that new printings don't include it.

This is not an area where I have much expertise, but it wouldn't surprise me if that wound up being an expensive task. For one thing, scanners that sort/read paper currency might need to be modified. So I wonder what the impact would be and whether it's really worth it.

Taking another example - most of the times taking an oath requires the "so help me God". Not sure it's worth it.