Lots of writers use initials for lots of reasons, one of them being to de-emphasize the sex of the author. For instance, G. M. Malliett, a woman, writes a series about Max Tudor, a man. E. J. Copperman, a man, writes three series in which the sleuth is a woman.
To get a sense of what's going on in the marketplace for the kind of book I write, I went to the website for Malice Domestic, a conference for fans and writers, devoted to the "traditional mystery," a form typified by the novels of Agatha Christie. By making a list I found that about equal numbers of women and men use initials instead of a first name. Some of their sleuths are the opposite sex, some are the same. So there does not appear to be a standard practice for this.
My sleuth is an art historian named Nicole Tang Noonan. Will potential readers be less attracted to a series of books about her if they are written by "Rick Homan?" Would a reader be more likely to give them a try if they are by "R. L. Homan?"