Terrible idea. Not just to introduce the internet to an uncontacted tribe, but to also perhaps invent the internet in the first place (I state, while posting this comment on the internet).
I don't want this to be a critical but reactive comment of "I hate where this is going, but that's the way of the world these days, I guess." I don't want this comment to be one big shrug.
The internet is one of the greatest pinnacles of human mediocrity ever conceived. There is so much that can, and has been, done with the internet; but all that some people do with it is "look up pictures of kitties and titties". Or maybe watch cheap anime. Or share empty memes. Or glue themselves to social media in a way that makes them oscillate between dopamine microrushes from "likes" and getting in piss-fights with people who disagree with them. (EDIT: And swimming idly through celebrity gossip.) Basically, do anything that makes them comfortable and gratified and mildly amused; while their rights and potentiality of achievement greatly suffer.
One of my favorite podcasters mentioned, in response to this situation with the Marubo tribe; that any society that utilizes the internet does not use it merely as a tool, but centralizes itself around the internet. And because of the damage that the internet has caused the world (with one aspect of this damage being unmitigated and unregulated porn access and distribution) while still being a useful thing, I hope to live long enough to see a post-internet society. Most people would look at the phrase "post-internet" and think that it means "after the arrival and social instilling of the internet"; in this instance, I mean it as "after the internet declines and diminishes in widespread relevance". I think that there would be no shortage of benefits to the world not just de-internetizing itself, but also re-primitivizing itself.
Failing such a tall order as described in the last paragraph, I hope to, at least for myself, start having weekly instances of internet abstinence. I am able to do it once here and once there, and I always appreciate when I can (i.e. anytime I go camping). Reserving one or two days a week, every week, to stay offline could really do wonders for productivity in other aspects of life. I would like to start doing something like that while it is still the 2020s.
In October 2022, I went camping in the mountains several hours north of my locale. I did several hikes, set a few campfires, and enjoyed the amazing, remote outdoors. I camped in a spot roughly halfway between a town of 900 and a town of 40, which were about 40 miles separate from each otr. One of the best aspects about the camping trip was that I spent five overnights without having used internet, with phone connectivity being nonexistent at the sight, but only coming in anytime I visited the bigger town. As awesome as that experience was, what would it have been like for ancient peoples to live their whole daily lives in more technologically, resourcefully, and infrastructurally restricted ways (or at least the way such a thing is conventionally understood as such)?
More people, myself included, should adjust themselves toward adapting to the prospect of their internet disappearing, perhaps for longer stretches. Humanity was okay before it came around. Wiring every home to an overlording database and several megalithic databases therein has, for many reasons, made us less okay.