Actually... not.
When The Lion King was being produced, there was another sure-to-dominate Disney movie being made at the same time: Pocahontas. Therefore, when The Lion King was still fairly fresh, quite a few members on the production team jumped ship (pun intended) from TLK to Pocahontas.
And throughout its production cycle, it was repeatedly stated that people felt like Pocahontas was going to be THE BIG THING, while The Lion King was just the Disney "B" movie. So they had fun with it, and did what they felt like. And nearing the end of the production, the team started to feel like they really had a movie, and went all out to make it the best they can (such as completely changing the entire intro to Circle of Life only)
Even then, when they finished the movie, it was still felt that The Lion King was either going to be a really huge hit, or a serious flop. Good thing it turned out to be the hit that it is.