Gynaecology is the branch of medicine that deals with functions and diseases peculiar to women (OED). In so far as there is "biblical gynaecology", I suppose that the material that would come closest would be the mention of the womb and breasts in Luke's Gospel (Luke 1.41,44, John the Baptist jumping in Elizabeth's womb; Luke 11.27-28, "Blessed is the womb that bore you . . ." and Luke 23.29, ". . . Blessed are the barren, and the wombs that never bore"). But this is not what Wallace and Burer are discussing in their article. Rather, they are discussing the gender of the name Junia, and asking also whether she was indeed an apostle. This is not gynaecology, Biblical or otherwise.
My surprise at seeing the expression in New Testament Studies sent me to the net to see if it is used elsewhere and it seems that one of the authors of the paper in question, Dan Wallace, has a piece called Biblical Gynaecology in which he comments:
The issue of the role of women in the church has become so central to how many Christians think that it even deserves its own theological label. Frankly, the best expression to use is “theological gynecology,” or “the doctrine of gynecology.” Too many associations with the medical profession will prevent some from seeing how appropriate this is at first. But ‘gynecology’ simply means ‘the study of women.’ And ‘theological gynecology’ means ‘the theological study of women,’ or ‘what the Bible says about the role of women.’ So I’ll use it sporadically throughout this paper.But gynaecology does not "simply mean 'the study of women'", even if that is the etymology of the word. It has a specific reference to the medical profession and to issues connected with female reproductive organs. Rather than seeing "how appropriate this is", a moment's reflection confirms how problematic it is, especially if one is aiming at a discussion that does not unduly prejudice the interpreter before one has examined the texts. It is difficult to see how it can be helpful to use terminology that risks reverting to androcentric stereotypes in which a woman's identity and function is viewed solely in terms of reproduction.
I must admit that I don't even feel comfortable with this discussion being cast in terms of "the study of women" in Paul. Rather, it's about the study of men and women in Paul. That might sound like a fine distinction, but I think it is important. Casting the debate in terms that focus specially on the status of "women" in Paul's letters tacitly assumes that maleness is the norm, the expected standard for authority and status that is challenged by apparent exceptions like Junia. The same scholars do not speak with surprise about "andrology" every time a male authority figure appears in the text. The very problematizing of the female figure of authority as if it is in some way abnormal or surprising already casts the debate in terms that prejudice the outcome.