Tron was released. I know this contains CGI animation, though I’m not sure if it’s the first. It was released before The Black Cauldron, which is suggested as the first of Disney’s films with CGI animation. Though I remember and know Tron has a lot of Computer Graphics used.
Kushner, D. (Producer), & Lisberger, S. (Director). (1982) TRON [Feature Film]. United States: Walt Disney Productions
Ultimate History of CGI. (2018, February 15). TRON (1982) - First combination of CGI and live action (HD). YouTube. https://www.youtube.com/watch?v=5UMJHAdEhMI