No, there has not been a blog on that subject on this site. We had a blog a while back on the MJO in general, and how it can interact with the ENSO state: https://www.climate.gov/news-features/blogs/enso/what-mjo-and-why-do-we…

In any given week, the MJO phase always has some effect on ENSO, either promoting an event, counteracting it, or having a neutral influence. When an El Nino gets as strong as this one did, the MJO influence may not be easy to note during the peak months. It is easiest to see during the development phase in spring and early summer. Maybe a blog about its effect on the 2015-16 El Nino is not a bad idea.