It is from the last lines of the article
@renarde posted above. It describes the hamlet of Boulard as a ghost town of 5-6 houses at the end of a long unpaved road only accessible by 4x4. Because it is not a through road or close to a junction on a main road, I doubt the security camera could have captured anything related to Emile's disappearance.
Here is my synopsis, based on a translated version. I'd love to know more about what seems to be hinted at in the translated article, but I am not bilingual. So what follows is MOO after reading the articles in the French media that you and others have shared with us.
Five friends and their families purchased derelict homes and built them into vacation homes in the late 60s/early 70s, centered around a far-right worldview with the Catholic Church (pre-Vatican II, that is) in charge of secular affairs. They modelled themselves The Kingdom of Patagonia, after Jean Raspail's nativist and racist works. Over the years, there have been apparently been schisms and feuding among the founding families. MOO, what I gleaned from the articles.
According to the article below, it seems a smaller, reconstituted group (which included Emile's maternal great-grandfather) remained in control of the hamlet and it was centered around the chapel. That is where the camera was. It was there for two years and removed recently. It captured the few, rare hikers who came through. Unless Emile was kidnapped by people formerly associated with Boulard who used it as a base camp in their plot, which would be quite fantastical, the arson and the security camera probably have no bearing here. I am certain authorities are investigating the possibility of involvement by rivals on the far right as well as groups opposed to them. But even so, Boulard is unlikely to be relevant.
Disparition du petit Emile au Vernet: L’enquête du journal Le Parisien qui interroge