Intellectual property issues (legal, and otherwise) are complex and quite nuanced. Both in doing the "legal" thing and the "right" thing, it's often not black and white.
I'm not really sure here...if you do have the plans, and you get a digital copy (from a "right" thing perspective) it's really only saving you the time, by another helpful person. The legal perspective is more complex (assuming Van's disapproves).
But, also very easy for those plans to wander into the intertubes and be reasonably findable by those interested in RV's. And some of those may never move beyond plans, never having made a purchase from Van's. But taking up the music piracy debate, you could argue that those plans being more freely available would make people more likely to build RV's with greater exposure, at no cost to Van's... Who knows?
Would be interested to see what Van's thinks about it now. If they had a "digital option" for extra money to throw in a CD with the preview plans binder, I would have bought it. It's also nice that I can take digital notes on the PDF's while sitting at my PC...without munging up my printed set.
Note that I'm not making any argument or point here. Just talking outloud in general.