Animation Source Forums

In the first script Kovu should be the true son of Scar and Zira, but the directors made him the adopted son of Scar probably to avoid the "incest" arguments. So I think that the directors didn't changed Kovu's design too much since the first script, they only changed some character's lines to confirm that is okay to Kovu fall in love with Kiara. I mean, despite the fact the movie was tagged as "G" (Everyone), it was also made especially for children, and the producers of TLK didn't expect children to have so much "hype" over some characters details...