Contact them and explain that while you can fly to France, you can't fly home to Reunion. Surely it's wiser to prevent people from traveling half the globe in times of a global pandemic.
So it's not a matter of flights being available or not, as we can still fly to Belgium. It's a matter of the embassy realising in times of travel bans, it's far wiser to leave people where they are rather than letting them cross half the globe!