The former repo at Bitbucket will be maintained (no more new commits) until later in 2017. I will give you sixty days notice before taking Bitbucket version offline.
Also, a gentle reminder: the NVDA Add-ons organization at GitHub is staffed by leaders of the add-ons community and is intended to serve as a collection of repos used by majority of add-ons, such as add-on template, development documentation, add-on wizard and what not. Thus, please don’t use the organization as a venue for hosting your own add-ons - these should live in your repositories, not with the organization. Speaking of development docs, the Bitbucket version of the devDocs repo will be moving to the GitHub organization before end of spring (end of May at the latest), and I will update the add-on dev guide to reflect features added and changed in recent NVDA releases.