So it helps to look up this tribe in Wikipedia. It turns out that they have been the stars of documentary film going back to a 1990 BBC feature. Their sequel, Aluna, was released in 2012.

https://en.wikipedia.org/wiki/Aluna

The film appears to center around their quest to obtain gold thread in London. It says the tribe has learned the art of filmmaking, in order to embed the documentarians among their own people. They also have participated in U.N. events.

The drama is framed as "Older Brother warns Younger Brother" about the dangers of modern technology and progress.

It seems safe to say that the tribe is speaking with one voice here, or at least authorized their leadership to proceed with this path, and release of the manifesto is a related activity that also emanates from authentic sentiments and teachings among the members.

So here is the 2012 film, Aluna: https://youtu.be/ftFbCwJfs1I?si=BzaFqTOLCpjE_EBh

The original 1990 documentary: https://youtu.be/9_7aZGShHbQ?si=9BdgVH38jzGoJEV1