I responded to another poster in this thread about my doubts regarding the language tracing attempts in the OP.
Regarding faulty information based on dubious studies, it is common, unfortunately. Not all people who claim to be scientists or experts in a field are what they claim to be. Not all people who actually are scientists are good ones, just as not all engineers are good ones.
There is a tremendous amount of misinformation about Native societies and customs due to films, fiction books, and New Age cult appropriations of Native practices by people who think it's cool to take on their fantasized notions of Native people. There is also a lot of deliberate disinformation based on racism or just a desire to make a buck off of phony "research" and stories. There is misinformation due to sloppy research and personal biases of incompetent scientists.
I have encountered a lot of misinformation about Native people online and in person. There will always be people who distort or misinterpret information, or who just make it up. People of other cultural identities and ethnicities in the US and around the world also face misinformation or lack of information about themselves and their backgrounds. In the US (and abroad, I've discovered) Native people are a popular target for sloppy science and fantasy stories.
Yes, many unknown people have existed in the past everywhere in the world that we will never know much, if anything, about. When evidence of lost groups is discovered, any conclusions about the evidence and people are imperfect. Good scientists know that.
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