The last article posted on this site was on March 2016 and before that an article was posted on October 2015? What could be the reason?

IIRC articles have been locked for a long time.

I believe you can still write articles for the site. The problem is making sure they are actually your work and not someone elses. There was a user that had their articles removed because it turned out he was taking credit for the source code and parts of a book for beginning C++ or beginning C++ game development or something like that.