That is actually the best idea... Reshape the island, remove the fort and back half, and fill in the river retaining a loop where the fort bridge is... The new reclaimed land from the rest of the river could be for Villains, create new settings along the river for the newly shortened River boat journey and a draw bridge for TSI... Also an expanded real restaurant on the island looking over Liberty Square. Perhaps it could even be a Tiana Restaurant... Perhaps even adding to and upgrading the features on the island...new additional things to explore.... Put Cars in DHS where it is a better fit for the tone of that park...
Or move it over to the Speedway location....