The Last Unicorn

Seeing The Last Unicorn in the theater as a kid I really liked the art style and story. It was a real alternative to the stuff Disney was putting out. Rankin and Bass had such great style to their animations. Someone recently told me some of those who worked on it went on to start Studio Ghibli. Is that true?
I've been reading the book with my daughters, and made some fan art for them. This was done in Procreate on a tablet.