I agree with you, but just to be completely fair:
Mulan has a
Mulan 2
Beauty and the Beast has its
spinoff.
Hercules has a boatload of mythology to go along with him (assuming they can depict endless rape by Zeus as child-appropriate)
Tarzan has a
sequel
Aladdin and the
King of Thieves
Halloween Town is used up, but there are a series of other movies of the same animation type
Atlantica with
two sequels
100 Acre Wood (LOL like you could use up the stories in this series)
Port Royal and its two sequels (as though I have to link this)
Pride Rock has
multiple spinoffs and
sequels
Tron would most likely be unaccessed in KHIII or its spinoffs
Alice in Wonderland was dropped.