Tesla has extended their pilot for non-tesla vehicules, see the following site: www.tesla.com/nl_BE/support/non-tesla-supercharging#selected-countries
can these chargers be added to be available for other vehicules?
Sample of Laxou France. They don't have the tesla logo on the map, so that might be the reason you did not see it yet, but they are used in planning if they make sense.
attached is a visualization of what chargers are currently in this pilot