I think the key quote from the article is from the think tank or "ideas laboratory” Terra Nova. This suggests that for the left the priority is no longer the working class:
"In a document entitled
The France of Tomorrow, Terra Nova said the country would be “younger, more diverse, more feminised”, and declared: “The working class is no longer at the heart of the leftwing vote”.
You are correct that the article is from 2015. The reason for posting it is that I've seen nothing to suggest that a change in direction has been adopted. You have to ask in those circumstances who exactly the working class are likely to logically vote for. A left that has turned its back on them or the far right who explicitly profess to speak for them.