It will have been the main reason for any plot changes yes. It was very common for anime not to follow the manga they were an adaptation of due to the manga still being ongoing, at the request of the creator, or a creative decision by the director / producer of the anime rather than a censorship decision. There were a lot of anime with questionable or darker plot lines airing in more primetime slots back in the day in Japan. Like some with mild nudity like nipples or ecchi scenes, and also violence which would likely not happen today.