Walking back from dinos has much less to do with "ceding dinosaurs to the park up I-4" and much more to do with them just lacking a vehicle or existing concept to anchor them to. None of their dinosaur-centered films met expectations. Indy was the obvious choice once their Tropical Americas concept started coming into focus.
Walking back from Dark Kingdom, as I believe they're doing, has much less to do with "ceding monsters to the park up I-4" and more to do with their ability to measure up to expectations with such a large creative pool and long-festering interest in the concept.
The "Villain Land" concept has been armchair-imagineered for so long, it's grown to a Beastley Kingdomme-like mythos. Lovely material for a coffee table book, but impossible to meet expectations as a real place.