I think Pinocchio is a believable example of a normal relationship, because they don't meet until they're middle schoolers. For the Westermarck effect to take place, it has to be co-habitation and shared carers/parents, from early childhood
Plus the absurdity of the uncle scenario is explicitly acknowleged by the entire family. There was never any family expectation of a true uncle/niece relationship.
I don't know 9 Times Time Travel. Could the relationship in Pinocchio be a cheeky satire of that element in 9 Times...?