“Please rest assured that your concern about the need for diversity and authenticity in this project is something we hear and take seriously,” he wrote. “All of us on the creative and producing team hope to continue this conversation, not just about ‘The Prince of Egypt,’ but about diversity and authenticity in casting in all the art we create.”

In a telephone interview Scott Schwartz said that “Prince of Egypt” was “a show that’s about inclusion — we wanted to create a diverse and inclusive show, and I think we will.” He added of the controversy, “We’re trying to address it and learn from it, and moving forward, whatever journey ‘Prince of Egypt’ takes, believe you me we’re going to be thinking about it.”

Bill Damaschke, a former DreamWorks executive who is now a Broadway producer and is overseeing development of the musical with Dori Berinstein, made a similar pledge, saying in an interview, “When we made the movie, we had every single religious consultant working on the film to make sure we were attentive to the many sensitivities, and I believe what we’re seeing is that there needs to be as much attention to culture, religion and race in how this gets presented in the future.”

It is not at all clear that the show will ever get to Broadway — it is being developed, Mr. Damaschke says, in response to requests from schools and regional theaters for a stage version they could perform.

But the project is destined to receive outsize attention in part because of the prominence of those involved: “The Prince of Egypt” was a hit as a film, with an Academy Award-winning song; DreamWorks, of course, has been a big player in the entertainment world; and Stephen Schwartz is one of the most successful composers in musical theater, with credits including “Godspell,” “Pippin” and “Wicked.” (The book of “The Prince of Egypt” is by Philip LaZebnik.)

The skin color of ancient Egyptians is the subject of debate, and this is not the first time that the casting of performers to play characters in ancient Egypt has drawn concern. In 2014, there was sharp criticism over the largely white casts for two films then in development, “Exodus: Gods and Kings,” and “Gods of Egypt.”

The reaction to the “Prince of Egypt” reading seems to illustrate the increasing willingness by performers to speak up, and the ability of social media to amplify their concerns. And, after a theater season with an unusually high number of black, Hispanic and Asian-American performers, some are using their visibility to call attention to issues: Next week, a group of performers and writers, including the six-time Tony winner Audra McDonald, will appear at Columbia Law School for an event to support the Black Lives Matter movement.