Grade changes and historical achievements

Wolfgang Güllich's Action Directe in Frankenjura from 1991 is known as the first 9a, even if the proposed XI german grade, at that time, was translated to 8c+/9a. Today many in the UK scene think Ben Moon's Hubble from 1990 also should be upgraded to 9a. It just might be that in a few years, the history books have to be rewritten saying Moon put up the first 9a in the world? An example where the history books already have been rewritten is Bernabe Fernandez Chilam Balam which originally was claimed to be the first 9b+ in the world. Now it is considered 9a+ or 9b. Based on this list we can see that like a third of the 9a ascents now have been listed as 8c+/9a. The most known example of a grade change is Era Vella in Margalef. It was repeated and confirmed by some 20 climbers before Jonathan Siegrist said that for him personally, he did know other 8c's that were equally hard. This together with also that many of the repeats could be considered personal best, made some others say it should be down graded. In one way this shows that there are no such thing as confirmed grades that can be written on stone and the same goes for historical achievements. Grades will always be subjective and in practice it means that most probably we will see the history rewritten when it comes to first of the grade. In the same way, this means that professional climbers' CV's also need to stay updated.