That has been brought up a couple times when they were building the store, ironicallyA whole Spongebob land (while structure of Toon Lagoon may be perfect for it) would probably be overkill in that the character, and his world, is pretty one note.
Honestly, I think a Spongebob re-theme of ET would be spectacular. The ride system is perfect for that sort of character.
They could honestly turn Comic Strip Cafe into the Krusty Krab
Blondies could be the Chum Bucket
The main stretch could be Bikini Bottom
Popeye becomes a raft ride with the Flying Dutchman, obviously the boat would be re-skined
Dudley becomes a ride through the famous locations (Glove World, Jellyfish fields, Rock Bottom) trying to stop Plankton after he steals the Krabby Patty formula
You could even make the TL theater a Boating School family coaster
Just musing