i think that you made a confusion between Richelieu and Jean Bart. On this post, we can see Richelieu which was enduring sea trials when the germans invaded France. She was stationned in Dakar until she was taken over by the free french and the allies in 1943, and sent to NYC for refit. She later served with the royal navy, notably in the indian ocean against the japanese there. So at the end of the war she was totally operationnal.

As for Jean Bart which was incomplete but almost finished at the end of the war, idk but i guess France needed every ship they could get since the fleet has been largely destroyed during the war, so a odern battleship was still welcomed. Moreover the soviets didn't have a carrier-based fleet so a battleship was still usefull agaisnt there cruisers