The title “rabbi” is indeed significant. This can be seen by the fact that when Sara Hurwitz was called Maharat there wasn’t any outcry, but when she was given the title “rabba” that is when the controversy really broke out, even though her job description didn’t change in the slightest. Does this mean that there was no objection to a woman functioning as a rabbi as long as she didn’t have the title? Only after she was renamed “rabba” did the RCA adopt a resolution rejecting the “recognition of women as members of the Orthodox rabbinate, regardless of the title.” Yet despite that resolution, there are synagogues where women are still serving, for all intents and purposes, as members of the rabbinate minus the title.
Marc B. Shapiro, “Answers to Quiz Questions and Other Comments, part 2”, The Seforim Blog (25 March 2012), n. 6 {http://seforim.blogspot.com/2012/03/answers-to-quiz-questions-and-other.html}