I don’t speak this language and have no idea of this culture, but as always we must be careful as any literal translation from one language into another often conveys a different meaning, even when the words are the same.
Today, haka is used as a sign of respect and is performed on important occasions, such as sporting events, weddings, funerals, and powhiri (a traditional welcome).
Lorde performs one of her songs also in Maori (the song’s OV is in English, the song is called ‘Solar Power’). You may also be in interested in Olivia Foa’i, a singer who also performs in Gagana Tokelau, the indigenous language of Tokelau, a collection of atolls between Australia and Hawaii, and in this story.