For fans of long-spanning franchises, keeping the details of the universe consistent is only logical. With 57 years of stories in television, films, books and comics, Star Trek has a whole galaxy. Thus, what matters most is Star Trek canon, much of which came from The Animated Series. However, Gene Roddenberry liked to pretend the cartoon never existed.
Source：https://www.cbr.com/star-trek-canon-the-animated-series-concepts/
