How Genuine is the Catharsis of "A Raisin in the Sun"?

"A Raisin in the Sun" ends with the Younger family deciding to finally get out of their "rat trap" in the Chicago ghettos and move to their new house in Clybourne Park. The play ends with a suspenseful confrontation with Lindner in which Walter has a change of heart and realizes that their family has to move out and face their new white neighbors whether they are welcome or not. This ending leaves the audience with a feeling of hope and triumph, and definitely catharsis. However, as we read in the packet about Lorraine Hansberry and her play, the original closing scene was of the Younger family as they sat, armed and in the dark of their new living room in Clybourne Park, waiting for the white mob to come get them. This ending gives a very different feeling than the revised version, and it leaves the audience in suspense. I would say it lacks catharsis and the feeling of triumph that accompanies the current ending of the play. If Hansberry had left this original scene in the play, the message would be different and it would not seem that racism was dying, but that it was winning. All it takes is one extra scene at the end to completely change the meaning of the play. You can take any play, book, movie, or story of any kind and add something extra to the end--perhaps the next untold part of the story--and it would change the meaning. Stories end at strategic points to leave the right feeling with the audience and to portray the right message. Take Harry Potter for example. The last book ends with Harry defeating Voldemort and then fast-forwards 20 years and shows Harry happily married to Ginny and living life happily ever after. But what if you added one last scene about a new evil wizard beginning to plot his plan to take over the wizarding world? The ending wouldn't leave the audience with a sigh of relief, but with a gasp! People would wonder what it was supposed to mean: was the message to say that evil can never truly be eliminated? Obviously that is the complete opposite of what the Harry Potter saga was supposed to teach, but something like that could happen after the events of the story, just like the Youngers could get killed by an angry mob. You can always wonder what happens next after a story ends, but sometimes it's best not to. Once you start imagining the unwritten events after an ending, anything can happen and it can lead you away from the purpose of the story.