Delete interpolations if all addresses are known?

Yes. Address interpolation is just a method to identify large address range in a row. If each address is then mapped individually, it is not anymore necessary to keep the lower accurate elements (the address interpolation lines).

This is happening daily in OSM : for instance, a first contributor creates a 'school' with a node (POI). Then somebody else is adding the school building polygon. Then he moves the 'school' tags to the building polygon (or even better, to surending polygon covering exactly the school property) and removes the original POI. The polygon is more accurate than a simple node.