That older info about Napoleon is from a series of snippet stories (like, only a page long) where Lelouch tutors Suzaku about Britannian history. (I got one with one of the CG DVDs I bought in the past, though strangely, it didn't come with all of the others.) There was also a short little video clips for it, which were on youtube once upon a time I think, though I don't know whether it's still there. (I forgot the name.) Considering that, it may be that the creators deemed that these short stories wasn't important enough that they had to follow the info released in them. As for the EU's actual name, that's pretty much also up in the air. While it has been referred to as "Euro-Universe" in most printed materials, it was referred to as "European Ultra-Union" in the CG light novels, so it's hard to say whether Euro-Universe is definite or just a temporary name they came up with in the past to fill in the details, since the EU wasn't the focus of the story until now. Hopefully, they'll finally make things clear in Akito.
Also, according to a tidbit from the Geass Project twitter page (
https://twitter.com/intent/user?scre...e=GEASSPROJECT), the blond-haired girl who appeared at the end of the Kiseki no Birthday picture drama (the one that was sitting next to Nunnally, Tianzi and Kaguya as the leaders of all the major powers, and who is, according to the Twitter entry, the president of the EU) will be appearing in Akito as well, so we'll finally know who she is.