Well, there was some consideration for it in the government, but it didn't have the courage and urgency to enact it in the time when it would have mattered, that is roughly towards the end of May when the British were withdrawing and the trapped forces were evidently not going to be relieved. For example the substantial forces protecting the Maginot line were left there as part of the last battle plan, but in that case would have to withdraw before early June when it was too late.
IMO there would be enough left to slow down the Germans and create a proper Brittany Redoubt, but not enough to stabilize the front in France. Regardless this would remain unviable long term, at best it would be a way to evacuate more forces as part of a plan to fight on but without any local industry it could not be sustained beyond a few months.
Again, all of this is dependent on the attitude of the French government and there wasn't really a basis to think it would have had such determination. Although as of late May the "fight-on" faction was actually pretty large and arguably larger than the defeatist faction. But you need to act quickly otherwise the latter will prevail as OTL.