I kinda understand some of the arguments and sensitivities and some examples on the website are dumb but it's also dumb to deny that French language can't be associated with France. I bet people in Quebec and Niger can make the connection when they open the dropdown that this will be the language they speak.
Let's not lose the practical aspect of quick recognition. I know there might be 20+ languages spoken in Niger but they won't be on your run-of-the-mill eshop. The dropdown will have 10 options at most and the person in Niger can make the pick faster with the French flag. The bigger conondrum might be which flag to choose for Arabic.