See: http://www.playonline.com/pcd/topics...06/detail.html

Condensed:
As announced in March, we will continue minor version updates through and beyond April 2016. Each month we will bring you battlefields, Record of Eminence additions, balance adjustments, and bug fixes. Vana'diel's story does not end here, and in the near future we are planning a version update for December. We will have further updates in the weeks ahead, so stay tuned for more.
Aside from that, the game will still host a plethora of (seasonal) events, log in campaigns, etc.

The only things really ending are the major storylines and game console support (per March/April 2016).