Yes, yes, we all know what happened OTL in 1940 when the Germans broke through the Weygand Line.
But what if it had held? The French had just recently received more than enough men and materiel to make up for what they lost at Dunkirk. So what if France's last defense before Paris had withstood the German onslaught?
Exactly what Stalin was hoping for happens, a long WWI style bloodbath while he re-equips and reorganises his military. Sooner or later the Germans and Russians will go at each other like rabid targs, but the Red Army will not be starting out with a wierd mix of obsolete tanks, artillery etc commanded by people chosen for political reliability rather than skill.
Possibly no or a different Pacific campaign, as this type of war would make the European colonial powers look like dangerous maniacs rather than a pushover to the Japanese. After all, we are looking at the French army retaining its older image as one of the best and most fanatical in the world, and look it up, they DID have that image which is why the fall of France was such a shock. All the 'knowledgeable' people had been saying pre-May 1940 that Germany was no match for France, the German army had expanded to quickly and the organisation was absurd, I mean whole divisions for tanks? Dive bombers to do the job of heavy artillery? The idea was obviously unworkable...