It sounds like it was the right call, too. Not only did the new sequence save parents from dealing with traumatized children, it also let Natasha’s death have a bit more depth to it. The Avengers: Endgame writers, Christopher Markus and Stephen McFeely, are “really proud” of the scene in the film, but as they also previously noted, they do regret not having time to “roll around in the grief” of Black Widow’s sacrifice.
Article source: https://www.cinemablend.com/news/2492527/scarlett-johansson-explains-why-her-avengers-endgame-death-originally-worried-her