It is a native language of a few thousand people, per the article.
Most Esperanto natives are from parents who don't speak each other's native language and use Esperanto to communicate.
That's not what "native language" means, tho. They can be fluent, but by definition there's literally nobody _natively_ speaking Esperanto.
That's not what "native language" means, tho. They can be fluent, but by definition there's literally nobody _natively_ speaking Esperanto.