The 47-year-old - one of the game's most respected officials - was allegedly referred to as "a motherfucking faggot" by Rondo after Kennedy ordered him to leave the court for a second technical foul during a game in Mexico City on December 3.
"I am proud to be an NBA referee and I am proud to be a gay man," Kennedy told Yahoo Sports. "I am following in the footsteps of others who have self-identified in the hopes that will send a message to young men and women in sports that you must allow no-one to make you feel ashamed of who you are."
Rondo, who initially denied making the comments, was given a one-game suspension by the league for "directing a derogatory and offensive term towards a game official and not leaving the court in a timely manner" after two other officials confirmed Kennedy's report.
NBA commissioner Adam Silver said: "I wholeheartedly support Bill's decision to live his life proudly and openly. Throughout his 18-year career with the league, Bill has excelled as a referee because of his passion, dedication and courage. Those qualities will continue to serve him well both as a game official and as a positive influence for others. While our league has made great progress, our work continues to ensure that everyone is treated with respect and dignity."
Rondo has an estimated salary of $9.5m (£6.3m) for the season, meaning that he will lose $86,300 (£56,900) as a result of the suspension.