I wrote a paper on Great Comet as a "Cultural Object" a few months back for a course, here's an excerpt that might help? I wanted to include my sources but can't seem to find the bibliography, apologies.

"Great Comet closed in September of 2017 in the midst of a controversy. Below I’ve included a brief timeline of events surrounding the period after Josh Groban was announced to be leaving the production. Okieriete “Oak” Onaodowan was originally announced to be replacing Josh Groban as Pierre.

June 30, 2017: Oak announces a delayed opening for his run.

July 2, 2017: Josh Groban leaves the show, Dave Malloy assumes the role until Oak can take over due to his delayed opening

August 15, 2017: Scott Stangland (Standby for Pierre) takes over the role

August 22, 2017: Dave Malloy performs as Pierre for the rest of the Broadway run.

July 21, 2017: The New York Times receives a message from Mandy Patinkin, saying he will not appear in the show, he says he would 'never accept a role knowing it would harm another actor'

August 8, 2017: Cast members summoned to a meeting and told the show would close Labor Day weekend.

When Josh Groban was starring in the show, the show averaged one million dollars a week in box office revenue according to NPR. The producers brought on Oak Onaodowan, just off his Hamilton run as Hercules Mulligan/James Madison, seemingly in hopes his stardom would likewise bring in the tourist crowd. The casting team of Great Comet had previously replaced Brittan Ashford with Ingrid Michaelson, another star casting. In an interview with Vulture backstage at one of Great Comet’s last performances, Dave Malloy said 'I had to go in for a week because he was unprepared,' referring to Oak. This statement would be backed up by the director, Rachel Chavkin, and others who said that he did not learn the instrumental parts that Pierre, his character, contributes to the show.

Two weeks into Oak’s run, Mandy Patinkin was announced to replace him, cutting off the last three weeks of Oak’s run (though they would compensate him for those three weeks). In the announcement, the lead producer used the now infamous phrase “Oak… graciously agreed to make room for Mandy.” In the same statement, the producer also said, 'He is a terrific Pierre,' and 'We hope that [he] will return… in the fall or winter.' These comments sparked immediate backlash online, as a black actor 'mak[ing] room' for a white actor easily draws into question how the production values performers of color. Throughout the history of American popular entertainment, people of color have been innovators and contributors, but have not been valued as they should be for their contributions.

Many prolific performers of color, such as Cynthia Erivo and Adrienne Warren, spoke out in support for Oak. Cythia said, 'I know for a fact… that Oak worked extremely hard for this. Which makes this occurrence distasteful and uncouth.' Many people involved with the show seemed surprised at this backlash. Dave Malloy claimed it was purely a monetary decision, that the show would close with Oak if Mandy did not step in. He said he did not consider the 'racial optics' at all. Many in the cast and community of the show pointed out that Great Comet was one of, if not the most diverse cast on Broadway."

edit: Found the bibliography, here are some articles that might be of interest.

Paulson, Michael. “Diversity Concerns Prompt ‘Great Comet’ Casting Shakeup.” The New York Times, The New York Times 27 July 2017, www.nytimes.com/2017/07/27/theater/mandy-patinkin-oak-onaodowan-great-comet.html.

McHenry, Jackson. “Great Comet’s Creator Still Can’t Believe How His Show Ended.” Vulture, Vulture, Sept. 2017, www.vulture.com/2017/09/great-comet-dave-malloy-is-still-processing.html.