If I have understood you correctly, you are referring to data migration. To the best of my knowledge I don’t think the system does a validation to check if the address entered is a valid one or is present in the address hierarchy. Address Hierarchy is useful more in terms of auto populating other fields such as District, State etc., when we enter a Village that is not listed it permits free text on all the address fields.
We are also analyzing the issue reported in parallel, but wanted to inform you that data migration should not have dependency on the address hierarchy table. As person_address actually stores the address itself and not the link to the address_hierarchy_entry table.