No. That's not at all what I am trying to say. I said that this is a major challenge, since the tendency is to prefer the language of the majority. If emphasis is placed on the minority language, which is somewhat of an exception, bilingualism becomes additive and excellent. Unfortunately, not all exogamous individuals do that. Only 29% of them do it. However, the number is growing, and that goes against all known sociological rules. For instance, educating rights-holders in Canada about the effects of the minority school's bilingualism would be an excellent way to inflate that figure.
Canada would be an example for the rest of the world and would prove that exogamy does not put an end to the transmission of two languages. Someone from Statistics Canada told me that a fair outcome in exogamous situations would be 50% of people choosing French and 50% of them choosing English. What would be fair for the country's human capital would be for 100% of those children to speak both mother tongues. That's very doable. Children can very easily learn two languages at a young age. I have some examples of that, as do you, no doubt.