Based on their rotation of park investments, I'd guess the first big project after Villains would be something for Epcot, followed by DAK and DHS
MK (New Fantasyland)
↓
DAK (Pandora, Harambe expansion, RoL, park enhancements)
↓
DHS (TSL, SWGE, MMRR)
↓
Epcot (GotG, Rat, Moana, TT, Spine...