Thankfully, they have changed course since the war and are now planning a new nuclear buildout as well as have removed the 50% cap. https://www.reuters.com/world/europe/french-parliament-votes...
Pre-war it only imported 17% from Russia, and like most European countries it has since switched to other suppliers. Turns out bringing LNG regasification plants online can be done in a few months, and plenty of countries are willing and able to supply that.
Besides, the claim I responded to was that the decline of nuclear in France led to a dependency on Russia for gas. The fact that Europe rapidly switched to LNG shows that this is not true, regardless of your opinion about anything else. Nobody is pretending that LNG is green, and biomass is heavily criticized for exactly that reason.