The third one doesn't work unless you add something to it.
As of next Monday, he will have been writing articles every Monday for 3 straight years.
The first could be improved if you say how long it's been going on. He's been writing articles every Monday for a year now.
The second could be improved by saying what happened to make it stop. He had been writing articles every Monday when he got that contract to write for a television series and had to give it up.
What does your friend object to?