It appears Mexico prior to 1998 denied Mexican nationality to those who were born abroad and obtained birthright citizenship there? After 1998 until recently they allowed it but only for one generation?
Most of the Americas including neighboring Guatemala granted birthright citizenship. Does this mean the child officially would have to obtain a visa to return with parents to Mexico and was that a difficult process for the family? Would a child be treated like any other Guatemalan despite parents being Mexican? Especially if they were “accidental” Guatemalans?
It’s interesting that countries like China they forbid dual citizenship, but they consider kids born abroad as Chinese Nationals that is unless the parent(s) had “settled” abroad at time of the child’s birth and their kids received foreign nationality at birth.