The key difference is that births like those (and this one) aren't about "we need more elephants," they're about which elephants survive and reproduce

Well, "[Raja] was the first elephant ever born at the Saint Louis Zoo and is considered a St. Louis legend. Male Asian elephant Raja, born amid fanfare nearly 31 years ago on Dec. 27, 1992, has three daughters at the Zoo..."

https://stlzoo.org/news/elephant-news