A questão é, na verdade, antecipada no filme , o que é um toque agradável.
De Wikipedia :
After the Gauls succeed in every task, Caesar agrees that they are gods, gives them control of the Roman Empire, and retires to live with Cleopatra in a little house in the country. Caius Tiddlus takes his reward by retiring to the Isle of Pleasure. In the village's celebration, Obelix asks Asterix if the Gauls really did conquer Rome. Asterix tells him that everything that happened to them was a mere cartoon, in which everything is possible. Obelix takes advantage of this and teleports himself and his wild boar meat to the Isle of Pleasure, where he is finally able to enjoy himself.
Assim, do ponto de vista do universo, os eventos de As Doze Tarefas do Asterix simplesmente não importam .