Jonathan Eig talks about some of this in his book Opening Day: The Story of Jackie Robinson's First Season. Jackie Robinson broke Major League Baseball's color barrier in 1947, so what's written deals with integration at that time, primarily talking about the coming end of the Negro Leagues as the Jackie Robinson experiment was turning out to be a success.

In regards to all the black baseball players that filled the Negro leagues and their future job prospects, Eig writes (p 172):

It was a thrilling time to be a Negro-League player, and a frightening one, too. Gone was the world they had known in which they had thrived. For some, the new world would offer undreamed-of-opportunities. For many more, it would mean the end of their careers in baseball. It almost certainly augured the end of one of the longest-running and most popular black owned businesses in the country.

Several pages later (starting on page 190), Eig goes on to talk about how black businesses were sources of pride, but inferior, so it was hoped that integration would bring equality, dignity, and opportunity. Also noted, some of the people in support of keeping black business alive were white people who were scared of integration and/or also profited from black businesses (like the black business's landlords).

Black Americans had developed many strong businesses in response to segregation, taking what they were given and making the best of it. There were black hospitals, black schools, black charities, black motion picture companies, black churches, black newspapers, black bus lines, black taxicab fleets. Though most of these businesses and institutions were sources of pride, they were also seen as somehow inferior reminders that black Americans had not yet been accepted as equals in their own country. Integration, many hoped, would bring equality, dignity, and opportunity.

Later, those feelings would change. Frustration would settle in, subtly at first, and then with force. Many black Americans would come to resent the fact that white people were setting the terms for integration and proceeding at a less-than-urgent-pace. They would complain that when white Hollywood producers hired black actors to attract black audiences, they tended to cast them as butlers and maids. But by the time many black Americans recognized what was happening, it was too late. Now, as black baseball fans attached themselves to the Brooklyn Dodgers, they also became familiar with the pleasures of the big-league game, with the voice of Red Barber, with daily box scores in the newspaper, with the sweet swing of Stan Musial. As a result, the Negro leagues suffered an identity crisis. Should the black leagues try to compete with the white leagues, or give up and serve as de facto farm teams? Should they try to hang on by embracing segregation, or accept what even some owners considered the greater good of integration.

“There is considerable apprehension within the ranks of Negro baseball these days," Wendell Smith wrote. “Owners of teams in the Negro American and Negro National Leagues are concerned because they fear that Organized Baseball is going to take their stars and subsequently kill Negro baseball altogether…. They contend they have felt the effects of Robinson’s drawing power already this season.” Smith tried again to be an optimist. If the Negro-league owners did a better job of promotion and presented games in a more “dignified and businesslike manner,” fans would remain loyal, he said.

The black newspaper writers were nearly unanimous in their support for integration, and so were the owners of the Negro-league teams, even though Jim Crow was essential to the success of both their industries. The few voices crying out for the protection and preservation of the black baseball tended to be whites, including Calvin Griffith, owner of the Washington Senators, who wrote that white baseball had “no right to destroy” the Negro leagues. He continued: “Your two [Negro] leagues have established a splendid reputation and now have the support and respect of colored people all over this country as well as the decent white people…. Anything that is worthwhile is worth fighting for so you folks should have no stone unturned to protect the existence of your two established Negro leagues. Don’t let anybody tear it down.” But the black press accused Griffith of dishonesty, saying his kind words for the Negro leagues were a clever way of disguising his opposition to integration. They noted Griffith, known as “The Old Fox,” collected a fair bit of money from the Negro-league teams who paid rent to use Griffith Stadium.

Various proposals were floated to save the Negro leagues, estimated at the time as a $2-million-a-year business. Some suggested the leagues should start recruiting white players. Others said the leagues should become part of white baseball’s farm system. But most believed Negro baseball was worth sacrificing on behalf of integration.

As one letter to the editor of the Chicago Defender said:

The protest of the Negro baseballs is as selfish as any plantation owner of slavery-bound men in the days prior to the Civil War. Their own interest is above that of their nation. This is an appeal to all Negros to avoid this, for their freedom means freedom to all men, and courage to men of other lands. Segregate yourselves and others will do no better.

And as a note, Wendell Smith, whose quoted by Eig, was an African-American journalist for the Pittsburgh Courier, a leading African-American newspaper, and played an essential role in Jackie Robinson's success, traveling with the Dodgers and covering Robinson extensively. And the Chicago Defender which had a letter-to-the-editor quoted, was another African American newspaper.