I think this is true to an extent - it's safe to assume that the Hollywood/New York/San Fran areas will largely look the same forever. It's just ingrained into the park's DNA, and I'm fine with that.
However, I think they can get creative with space to do some dark rides - even if they have to build vertically like Transformers. I think Villain Con could have been a dark ride - but the budget at that point was probably very low!