I stand by my original statement.
Leave "it's a small world" alone.
Something are awesome on their own.
Would you paint Tow Mater in the background of a Picasso painting?
Maybe...if it will fit a story line
Maybe we could place a Disney princess in the red head scene in Pirates.
Ariel the pirate queen
Maybe place the Mad Hatter in the ballroom scene in Haunted Mansion.
It could work
Or add the dancing hippos from Fantasia to the Jungle Cruise.

"it's a small world" is awesome just as it is. Updating the electronics, changing the lighting, doing something with the black 70's acoustical tile ceiling....those are all improvements I can understand.
Adding Disney characters to an artist's vision seems a bit blasphemous to me and if you do some research...you will find that Mary Blair's family felt similarly.
This ride was developed to promote world unity and to show children from around the world. Richard Sherman has described the theme song as a "prayer for peace".
Lilo and Stitch have other homes in the park. Disney characters can be found anywhere. They dont need to reside in "it's a small world".
I know what you are going to say.....they added Captain Jack to Pirates and it was very successful. Fine. Make a movie about children around the world singing about world peace and I will have a different opinion...but placing Jessie from Toy Story in "it's a small world" is wrong in my opinion.
Leave a classic ride alone. It doesnt need to be "improved".