A poster at Eurobricks was apparently told this as a result of an e-mail to Lego.
The marketing bit ... I don't know the exact wording and what not, but basically, as far as I understand it, in the UK (and maybe Europe too?), it's against the rules to sell a product based on the grounds that it *might* contain something extra. Basically, if it says on the box that it contains something, it has to contain it.
So, that means they can't randomly put them in the boxes ... it has to be given away in another deal, such as the assumed, buy a certain amount of SW Lego, get a chrome DV for free. Which is the same way the Mini JSF was given away a few years back.
Regarding the complaints you refer to, I would describe them as more like "why don't we get the chance to get these things?" (regardless of the delivery method) rather than how you describe