Well, yeah, but the rest of the article doesn't seem to use that definition of "true" bilingual? Because it just talks about immersion with native speakers. Either the article didn't deliver as advertised -- had a hook about "true" bilingualism (whatever that is), and then went on to explain how to raise a "regular" bilingual child. Or the article really just meant "regular" bilingualism and wrong in stating that it is rare.

(Or perhaps I just have a very skewed sample set and even "regular" bilingualism is rare)

Idk. Overall this article didn't sit well with me, for more reason than one (https://news.ycombinator.com/item?id=14830685).