Let me telll ya why they think its a disney movie

Okey I have seen Thumbelina as a child and alot of people think its disney because they are 4 voice over actors who are in disney movies.

Jodi Benson-Ariel
Kenneth Mars-Triton
Will Ryan-Seahorse
All from little mermaid

Then the voice of the beetle is in fact the same person who voiced that annoying bird in Aladdin way back in 1992. Hope that will help