I imagine this revenue is why Disney is so eager to build more and more timeshare resorts over cash rooms
I think there are two simpler explanations.
The simplest: the timeshare model compresses the ROI of a resort's development into just a handful of years during sales, rather than over the viable lifetime of the property. Because publicly traded companies are evaluated quarter-by-quarter, this acceleration is a smart move for the balance sheet.
Maybe another (and one I've been convinced of for a long time now): DVC shifts the risk of unexpected drops in travel demand from WDW to individual owners. This is important becase WDW is so highly dependent on air travel to make it work; Central Florida just isn't Southern California, Shanghai, Tokyo, etc.
If you think about it, the spigot for cash rooms was closed in response to 9/11, and really hasn't ever re-opened. The only cash rooms built since then are the completion of of Pop/AoA (which was already in progress when 9/11 happened and took more than a decade to finish), Gran Destino tower (built for convention business), and the Galactic Starcruiser (the poster child for specialty lodging).
In that same span, we've seen a steady diet of DVC rooms spread between new builds and conversions that
removed cash rooms from inventory: BCV, SSR (a complete conversion of the Disney Institute), Kidani, Jambo (partial AKL conversion), BLT (North Garden Wing conversion), GFV, PVB (partial Poly conversion), CCV (partial WL conversion), Riviera (partial CBR conversion).
And I think it worked. How much harder would it have been to get guests to come to Orlando during the beginning of the pandemic recovery without a chunk of DVC owners with use-it-or-lose-it points?
Also interestingly: Reflections was a departure from the "normal" development model in that it was mixed-use: DVC plus cash inventory. I don't think it is any accident that it was cancelled outright as a result of the pandemic. Furthermore, I'll bet a mickeybar that (a) that parcel will be used for DVC development in the next decade and (b) there will be no cash rooms as part of it.