They likely don't. It's a purely political move not a technical move. With the average length of the French work week, this will take a while to implement anyway.
Don't get me wrong, I think it's a great thought but I don't think it's more than a short-sighted reaction. Munich unfortunately faltered after a few years.
The french Gendarmerie already migrated to GendBunto, their own distribution. It took a while but it's now running on 97% of all workstations.
I wouldn't call this just political fluff.
