I'm never one to hesitate in criticizing Disney for replacing rather than expanding, but to be fair there has been or will be a good bit of actual expanding going on at WDW:
* new areas being built at DAK: the FOTLK area and Harambe marketplace in Africa, Pandora (yes, it is replacing CMM, but is a far larger footprint) plus even some new builds like Riverside Depot and Tiffins on Discovery Island.
* In DHS, Toy Story Land will be in mostly formerly backstage area, Star Wars is going to take over some of the current parking lot and backstage. The new flex theater was an addition to the guest areas
* In MK, most of the FLE was reusing old space but the BatB area was previously backstage
* while most of us agree that it doesn't fit in Epcot, the M&G hall addition to Norway is developing new space