This body was (on the German side) put in place by the Kultusministerkonferenz. Their recommendation don't "change" the language (and never could do so). It just says what administration and schools have to use. Everybody else is free to do whatever they want (and many publishers have their own version of the rules).

The changes that were made before (such as the ones in 1996, 1901, or 1876) were made by similar bodies.