I'm an autistic person who really loves disney characters. Disneyland with costumed characters are my world and the happiest place ever. I heard a few autistic people of any age who really loves Disney and when they are in Disneyland, they really enjoy playing with the characters. So I wonder is it very common that special need people of any age loves Disney characters.
The huge plus for autistic people in Disney is the simplicity and predictability - nothing ever goes wrong. You can rely on the system and if there ever is a problem, the cast members will sort things out to your delight - being just satisfied is not enough.
There's also the general feeling of the parks - sort of a low-level excitement mixed with calmness - and the park layout and theming make it very comfortable.
Some autistic people have a particularly strong interest in some areas - for you, this may be Disney, and I'm sure there are others as well! But people of any age and ability love Disney anyways :)
Much love <3