It's not as if they are holding themselves up as supporting Free Software philosophies (as opposed to Open Source), so where's the pretense?
If somehow it ever makes strategic sense for them to stop making use of the open source model, yeah, they'll stop. That doesn't mean they were pretending.
Anyone else get free Ubuntu CDs shipped to their house? I think I had 7.10 (Gusty Gibbon) shipped to my house back in 2007.
Otherwise, Mandrake Linux was my first "good" distro. I first tried one called Lycoris which claimed to be an beginner's distro with it's own DE, and it was impressive how well it handled setting up a dual boot installation and at the time it was a revelation that I could use a computer without Windows. I didn't begin preferring linux until I tried Mandrake with KDE 3, though.