French would definitely be the more obvious choice in this case

Both English and French are the official working languages of Cern.

They should include more languages than just English, but French is not by default the more obvious choice.

Right, but there are other reasons why French is more obvious, not just "by default" but based on arguments and reasoning. Or has HN truly forgotten about these things?

The previous poster was actually inviting you to expound on the other reasons.