Not sure why Air France wanting fluent French is worthy of possibly adverse comment, anymore that e.g. Lufthansa wanting fluent German (if they do) or Aeroflot wanting Russian, or BA needing functional English.
ICAO 6 for English is obviously essential on the flight deck world wide but bear flight crew crew have to deal with the back office staff, e.g. Ops, engineering, navigation, rostering, general admin, areas which are probably going to be manned by staff who may well not have a foreign language requirement....
BA advertise for level 6 but from what I have seen and heard they certainly look for a higher level of ability at interview.