The alleged expansion area that everyone is theorizing over would be nearly impossible to replace. Behind ML we have: the kitchens that serve all of Ghost Town and it’s restaurants as well as their offices and Crew’s Nest (employee cafeteria), Warehouse P which is where all our merch is stored as well as costuming for Scary Farm, the entirety of the park’s administration buildings, wardrobe, the employee training center, as well as various support for the park. Relocating all these services off site would be massively expensive and cumbersome, and take at least two years. The only plausible expansion I see happening is a replacement for the ML and its plot of landHypothetically speaking, if they go and take over portions of backstage behind Calico Rapids, Mystery Lodge, and Ghostrider; it could be plausible to see.
And before the question of KSF comes to play, they have locations around the park that they can use, as opposed to the backstage buildings.
Personally, if the expansion is more about adding more footspace and laying the ground for something in the future, it wouldn't be too surprising if you ask me.