If by "new" you mean an actual new construction, you won't find much in DVC outside RIV and arguably VGF2. The other DVC projects, CCV, VGF2, Poly, were flips of undesirable aging hotel rooms. This is a strategy that I can see continuing, hopefully Yacht Club.
3 of the last 4 DVC projects were new construction: Riviera, Disneyland Hotel and Polynesian 2. Reflections was new construction until sidelined by the pandemic.
Not really sure what makes something an "undesirable aging hotel room." Identical accommodations continue to operate as hotel rooms at the Poly, GF and WL, with wholesale refurbishments occurring every few years to keep them in line with expected guest standards.
Every DVC sale eats into the market for WDW Deluxe Hotel rooms to some extent. And WDW increased its inventory with 100+ high-end rooms in Galactic Starcruiser. Not every WDW deluxe hotel room is suitable for DVC conversion. They'll continue with a combination of both approaches as projects are identified which meet the needs of both DVC and the hotel.