Yeah that seems silly to me. I get the idea, but with their prices as high as they are, impulse buys aren't all that common. People tend to buy the models to serve a purpose in the list. Without the rules, the models serve no purpose.
Moreover, what does it say about their self-confidence if they are changing their release structure so they don't undermine their own sales with lopsided rules? In light of GW's recent financial woes, it looks like they're panicked and desperately experimenting with new ideas. Unfortunately for everyone, they did the exact opposite of what they should.
If it were me, I'd start with the book release. It is the one sale nearly GUARANTEED to every player of that army, so why not start off with a low-risk release? Fill it with pictures of all the up-and coming models, and keep your finger to the pulse of the community. Then adjust your production levels of each unit according to the interest they're generating in anticipation of release day.
I really don't understand that company anymore. Their policies so often work directly against their goals these days, and they can't seem to figure that out.