It's a term of art that straightforwardly means people who embrace AI-assisted programming. As opposed to the very large number of engineers who actively don't like it, or have enough change aversion to have avoided it.
replyAI-native should mean those who were born/came-of-age/started learning programming in the era of mature AI. It shouldn't be many people (relatively speaking) at this stage.
replyThe term that best suits "people who embrace AI-assisted programming" is AI-first programmers, which is what they literally mean by the looks of it. Clearly, they just use what they think sounds cooler.