After a $30.1 million opening weekend for his sequel "The Best Man Holiday" last fall, director Malcolm D. Lee negotiated a deal with Universal to write, direct and produce another installment of the ensemble romantic comedy, which went on to gross over $70 million in domestic box office, making for a profitable film for the studio, given that it cost only $17 million to make. So it really shouldn't be much of a surprise that a 3rd film was of interest to the studio; although, in this business, nothing is ever certain until it's actually made, even if it's formally announced.
Also, whether the ensemble cast has been locked in to return, isn't yet known. Although I expect those who survived "Best Man Holiday" to come back an complete what will be a trilogy.
Malcolm D. Lee apparently already had a 3rd film brewing on paper (before the last film opened), which, per the interview below, he's working on. As for what audiences can expect from it, we have no official synopsis yet, but, in the Vibe video interview that follows, director Lee, while on the red carpet over the weekend for the ABFF premiere of his cousin Spike Lee's "Da Sweet Blood of Jesus," teases us with a few plot points, intercut with star Morris Chestnut (also at the ABFF), who we can assume will be back for number 3, doing the same: