Some character changes were made in the revised bible as well, most notably, the replacement of Ensign Ro Laren. There was no dramatic or technical reason for this change. Quite simply, Michelle Forbes, the actor who played Ro, did not want to commit to a series. She liked the character. She liked appearing on occasional episodes of The Next Generation, but given the success of that show, it was quite reasonable to expect that becoming a main character on Deep Space Nine would be at least a five- to six-year-long career commitment. Forbes had other acting goals to pursue, and so declined Berman's and Piller's impassioned entreaties to sign aboard.
However, there was an unexpected upside to the loss of Ensign Ro. From the beginning, Berman and Piller had wanted to insure that there would [be] interpersonal conflict among the regulars, and, in hindsight, how much conflict could there be between Ro and Sisko when both were Starfleet officers? But if Sisko's Bajoran liaison officer was not Starfleet, if she was not under any obligation to follow his orders or even like him, a whole new character dynamic came into play.