The image indicates that it comes from someone named Eric Bricard.
Eric Bricard is a real person and his LinkedIn account his real. His LinkedIn account mentions that he works for Marina PLV.
His LinkedIn: https://fr.linkedin.com/in/eric-bricard-25b718103
"responsable grands comptes chez les ateliers Marina" = "account manager at Marina workshops"
A quick Google search of "les ateliers Marina" takes you to Marina PLV's wesbite, located here: http://www.ateliers-marina.fr/
On Marina PLV's website, they list Bandai Namco as one of the companies they have worked for: http://www.ateliers-marina.fr/references.html
This website's copyright info hasn't been updated since 2010, which is one reason to be skeptical. It means that we have no idea how long ago Marina PLV worked for Bandai Namco, since the entire website could be severely outdated.
With all this information in mind, I believe there are two possible truths should the image be a hoax:
Eric Bricard fabricated these images himself. He's a Smash fan with a lot of time to dedicate to creating this hoax. He may or may not have wanted his name to leak. On one hand it puts his job at risk, but on the other hand it's the only way that we're able to connect him to Marina PLV, which is his main source of credibility.
OR
The image was fabricated by some third party. This third party somehow became aware of Marina PLV, an obscure company, and its connection to Bandai Namco. They discovered Eric Bricard's identity and decided to use his name to make their hoax seem more legitimate. They also included fake promo material of The Grinch to strengthen the connection. In this case his name leaking would have been intentional since the connection to Marina PLV is clearly desired.
In both scenarios, if the image is fake, someone would have had to splice together the background of the mural and draw in all the gaps by hand. They'd then have to cut out each character render in order to rearrange them and draw over any cut parts. They'd also have to design seven renders from scratch.
I remain skeptical for one reason. It seems that Smash information is given on a need-to-know basis, especially this time where even Nintendo Treehouse employees were shown to be unaware of who's playable. For that reason I find it hard to believe that they would just outsource promotional material to some French company, giving them an image of the entire roster over a month before release.
And yet, if this is fake, it's either career suicide or the most elaborate we've ever seen.
http://i.imgur.com/UgOcJQG.jpg