it mainly focuses on the notion of not belonging:
- the River Rats choose to not belong
- the villagers are blindly conforming to Church traditions: the Comte actually writes Pere Henri's sermons. Evident when he lip-syncs the delivery
- the urn containing Vianne's mother's ashes is released with the North Wind so that her mother can move as she pleased; without taking Vianne and Anouk with her
but you can also say that Vianne and Anouk have brought the community to embrace their similarities and disregard their differences. Vianne's chocolate shop also brings people together (Luc and Armande)... and allows Josephine to realise her relationship with her abusive husband is just not right
hope this helps!