As far as I know they are directly coming from Dell. That's the "breaking" part of this manual, that a retailer as big as them are trying to explain how to get rid of Windows and just install a Linux distro.
I have a Dell Mini 9 that I got for >$200 years (2009?) that came with Ubuntu that I still use regularly. Now it's running Puppy Linux (Slackware based) though.
New XPS 13 Developer Editionhttp://www.dell.com/us/business/p/xps-13-linux/pd.aspx
New Inspiron 14 3000 Series Ubuntu Edition http://www.dell.com/us/p/inspiron-14-3451-laptop-ubuntu/pd?r...
New Inspiron 15 3000 Series - Ubuntu edition http://www.dell.com/us/p/inspiron-15-3551-laptop-ubuntu/pd?r...