My master plan for DCA (based on feasible/ realistic options amd things that have already been announced) would admittedly be very Pixar heavy but I think would maximize space, make sense, and bring a nice variety of attractions to DCA.
Bus Tranpo Expansion area - Santa Cecilia mini land / Coco boat ride
Hollywood Backlot - Monstropolis, Monsters Inc ride (willing to sacrifice Monsters Inc ride if more space is needed for Santa Cecilia and Monstropolis).
Hyperion / stage next to Hyperion - Doors coaster
Expansion Plot behind Incredicoaster - Inside Out Dark ride to go with Bing Bongs and Emotional Whirlwind
Simba Lot - Pandora and E ticket boat ride. And then I think you do Villains land here too. I know thematically it makes more sense over at Disneyland but that plot on that side is smaller so they may need to be a little choosier. Also not sure Villains Land is what you want right outside the Disneyland hotel. I think you go something Fantasy Springs Esque on the DL side.