I know of no other region of France where what you say isn’t true. Certainly nowhere in the South West, nor the Alps or the South East, nor Lyon/Grenoble.
Perhaps this explains why many Americans think the British are rather ‘reserved.’ It must be the fault of the Normans!
A Bonjour is always returned in our bit of Normandy. All the people my husband meets in his extended hospital treatment say Bon Courage too. 
Yes, this 
is how I find it too.
Even if one has t be the instigator of the greeting it is returned on 99,9999999% of occasions.