We know now that basic development has ceased on Battlefield 4, however that does not appear to be the end of the Battlefield 4 patch cycle. At lease one more hotfix will be released.
According to this Reddit post, there will be at least one more hotfix released for our beloved Battlefield 4.
There have been no client side updated to the game since December 2015, so this is a positive sign that the game has not been abandoned.