Just checked the amazon.co.uk "best sellers charts" (as referred to in that article):
As of now, Xbox One sits @5th place in "PC & Video Games" (PS4 is 4th).
In Germany (amazon.de), XBox One is 20th in the "Games" category (PS4 is 4th).
In France (amazon.fr), Xbox One is 167th in the "Jeux Vidéo" category (PS4 is 63th).
So, yeah. Make of that what you want. But "breaking pre-order records" seems to push the truth a little (at least in the EU).
Xbox always loses on Amazon even in the US from what I recall.
So it wont reflect true preorders.
You can be sure the broader retail chains breaking records report is true over the much smaller Amazon. Amazon rankings is fun I do it all the time but it's a small not representative sample, probably even influenced by the anti-Xbox fanboy wave on the internet.
I guess I'm trying to say Xbox is at a natural disadvantage in Amazon charts based on NPD vs Amazon USA rankings. So if it does well there it must be doing incredibly well indeed.