This is a great question. I am tempted to answer by saying - how could you not tell this story. Hwang's play is about the true story of how a French diplomat carried on a twenty-year affair with a Chinese actor, who posed as a woman! The truth was only revealed in 1986 when there was a charge brought against the diplomat for treason for passing secret and sensitive information to the Chinese opera singer, who was an agent for the Chinese government. You cannot make this stuff up. Just these facts alone make the story worth telling.
Hwang, however, also weaves into the play Puccini's opera, Madame Butterfly in interest ways. There are many reversals and a challenging of Eastern and Western stereotypes. The victim is no longer a 15 year old Japanese girl, but a French diplomat. In the least, we can say that the world has changed greatly since the time of Puccini.