According to the article, this is probably the first time in history that a same-sex couple is sent as missionaries anywhere.
Very few details are available about the presumptive missionaries, not even their gender, but I suppose more will be forthcoming.
There is some controversy about the appropriateness of publishing news of this kind, i.e. stressing someone's ethnicity, gender, sexuality, or the like. From the point of view of journalistic ethics, there might be a problem, but it's an interesting item, all the same.