I think the OP is referring to the recent spate of upgrades from the values to OKW and SSR.
This wasn't a routine thing, and certainly doesn't happen every time the values are completely booked. In fact, I only remember it happening once before.
This is just my opinion, but I think DVC is trying to finish up the sales at SSR. They still own a good chunk of the inventory there, and if they are indeed planning to build a new tower with villas at CR, they probably won't want to announce it until SSR or AKV sells out. I can't see any other reason for them staying mum about what's happening at CR, months after they tore down an entire garden wing.
So, I think the recent round of upgrades to OKW and SSR was at least partly a DVC marketing thing. There's no better way to convince someone to buy DVC than to have them stay in a villa. And if even 10% of the people who got that upgrade end up buying SSR, at $15,000+, then DVC came out WAY ahead financially.
So, sammyteach, these sorts of upgrades are extremely rare. I think your chances of getting one are very slim. Sorry.