German Isil identifier not very reliable

The German ISIL Identifer is not very reliable, i.e. the identifier DE-Hav2 was lately changed to DE-MUS-806511. Doing this BREAKS MANY SYSTEMS , i.e. the wikipedia ISIL in the infobox , which is crucial for dbpedia and other LOD Systems. Why not just keep the old URI and make a HTTP 302 redirect?