It could be argued that keeping such texts available would be educational in a historical sense and would show social attitudes of society at certain points in history. Also, erasing such books would be the equivalent to censorship (cue: comparisons to the burning of the books by the Nazis in the 1930s).
There were similar stories about the EU-wide adoption of the European Convention of Human Rights which did lead to a few 'stupid' cases, but generally seems to have worked well.
It will be interesting to see if it ever happens and if so, the text and how wide open it will be to interpretation at a national level...
VRN
The Nazis did not have to contend with the Internet. I think we may safely assume that technology has made censorship a practical impossibility. If adopted, all this law will do is make the Euros look stupid. IMO.